Publications

Boughton, GN & Crews, K 2013, Timber Design Handbook In Accordance with the Australian Limit State Timber Design Code AS 1720.1-2010, Timber Structures, Part 1: Design Methods.
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This revised edition reflects the changes in the Australian Building Industry since the release of the last 1988 edition, in particular the focus on timber and wood products as a key materials in sustainable construction.

Tao, M, Wu, C & Li, XB 2013, 'Numerical simulation of multiple fracture zones in underground dynamic loading processes' in Rock Dynamics and Applications - State of the Art, pp. 451-456.
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The excavation fracture responses around cavities in rock mass with initial stress were examined using three dimensional numerical modelling. In addition to the primary fractured zone in near field, numerical modelling generated the second fractured zone in far field, and an elastic non-fractured zone between the two fractured zones, i.e., the fractured zones and the non-fractured zone occur alternately around deep cavity. This finding proved that the zonal disintegration phenomenon can occur in underground excavation process.

Aghdamy, S, Wu, C & Griffith, M 2013, 'Simulation of Retrofitted Unreinforced Concrete Masonry Unit Walls under Blast Loading', International Journal of Protective Structures, vol. 4, no. 1, pp. 21-44.
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This paper describes an investigation into the effectiveness of using spray-on nano-particle reinforced polymer and aluminium foam as new types of retrofit material to prevent the breaching and collapse of unreinforced concrete masonry walls subjected to blast over a whole range of dynamic and impulsive regimes. Material models from the LS-DYNA material library were used to model the behaviors of each of the materials and its interface for retrofitted and unretrofitted masonry walls. Available test data were used to validate the numerical models. Using the validated LS-DYNA numerical models, the pressure-impulse diagrams for retrofitted concrete masonry walls were constructed. The efficiency of using these retrofits to strengthen the unreinforced concrete masonry unit (CMU) walls under various pressures and impulses was investigated using pressure-impulse diagrams. Comparisons were made to find the most efficient retrofits for masonry walls against blasts.

Aoki, Y, Valipour, H, Samali, B & Saleh, A 2013, 'A Study on Potential Progressive Collapse Responses of Cable-Stayed Bridges', Advances in Structural Engineering, vol. 16, no. 4, pp. 689-706.
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In this paper, a finite element (FE) model for a cable-stayed bridge designed according to Australian standards is developed and analysed statically and dynamically with and without geometrical nonlinearities. The dynamic amplification factor ( DAF) and demand-to-capacity ratio ( DCR) in different structural components including cables, towers and the deck are calculated and it is shown that DCR usually remains below one (no material nonlinearity occurs) in the scenarios studied for the bridge under investigation, however, DAF can take values larger than two. Moreover, effects of location, duration and number of cable(s) loss as well as effect of damping level on the progressive collapse resistance of the bridge are studied and importance of each factor on the potential progressive collapse response of the bridgeis investigated.

Ardalany, M, Fragiacomo, M, Deam, B & Crews, K 2013, 'Analytical cracking load estimation of Laminated Veneer Lumber (LVL) beams with holes', European Journal of Wood and Wood Products, vol. 71, no. 1, pp. 37-48.
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Predicting the load-carrying capacity of timber beams with holes cannot be performed by usual analysis methods if the failure of the beam is governed by the crack initiation and propagation around the hole at low load levels. Predicting the cracking load is an important design issue because it corresponds to the load-carrying capacity of the timber beam before the crack propagation. One of the models that can be used for the fracture formulation is that of a beam on elastic foundation. In this model a part of the beam is assumed to follow the conditions of beam with elastic foundation which has spring stiffness equal to the fracture properties of the material in the crack surface. Based on beam on elastic foundation model, the cracking load prediction is the target of the paper. Some closed form solutions for the beam with hole are presented. The formulation has been derived for two cases of pure shear and pure bending moment. Finally a semi-empirical formulation for combination of shear and bending moment in the section is presented. The model predictions are compared with the results of an experimental program showing good correlation. The analytical model can therefore be proposed for future revisions of codes of practice such as the Eurocode 5

Aslani, F & Nejadi, S 2013, 'Creep and Shrinkage of Self-Compacting Concrete with and without Fibers', JOURNAL OF ADVANCED CONCRETE TECHNOLOGY, vol. 11, no. 10, pp. 251-265.
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Fiber-reinforced self-compacting concrete (FRSCC) is a high-performance building material that combines positive aspects of fresh properties of self-compacting concrete (SCC) with improved characteristics of hardened concrete as a result of fiber addition. Considering these properties, the application ranges of both FRSCC and SCC can be covered. To produce SCC, either the constituent materials or the corresponding mix proportions may notably differ from the conventional concrete (CC). These modifications besides enhance the concrete fresh properties affect the hardened properties of the concrete including creep and shrinkage. Therefore, it is vital to investigate whether all the assumed hypotheses about conventional concrete are also valid for SCC structures. In the present paper, a numerical and experimental study about creep and shrinkage behavior of FRSCC and SCC is performed. Two new creep and shrinkage prediction models based on the comprehensive analysis on the available models of both CC and SCC are proposed for FRSCC and SCC structures. In order to evaluate the predictability of the proposed models, an experimental program was carried out. For this purpose, four SCC mixes - plain SCC, steel, polypropylene, and hybrid FRSCC - are considered in the test program. Several specimens were loaded and deformation in non-loaded specimens was also measured to assess shrinkage. All specimens were kept under constant stress during at least 364 days in a climatic chamber with temperature and relative humidity of 22°C and 50%, respectively. Results showed that the new models were able to predict deformations with good accuracy, although providing deformations slight overestimated. Copyright © 2013 Japan Concrete Institute.

Aslani, F & Nejadi, S 2013, 'Mechanical characteristics of self-compacting concrete with and without fibres', MAGAZINE OF CONCRETE RESEARCH, vol. 65, no. 10, pp. 608-622.
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Fibre-reinforced self-compacting concrete (FRSCC) is a high-performance building material that combines positive aspects of fresh properties of self-compacting concrete (SCC) with improved characteristics of hardened concrete as a result of fibre addition. Considering these properties, the application ranges of both FRSCC and SCC can be covered. A test program is carried out to develop information about the mechanical properties of FRSCC. For this purpose, four SCC mixes - plain SCC, steel, polypropylene and hybrid FRSCC - Are considered in the test program. The properties include compressive and splitting tensile strengths, modulus of elasticity, modulus of rupture, and compressive stress-strain curve. These properties are tested at 3, 7, 14, 28, 56 and 91 days. Relationships are established to predict the compressive and splitting tensile strengths, modulus of elasticity, modulus of rupture, and compressive stress-strain curve. The models provide predictions matching the measurements.

Aslani, F & Nejadi, S 2013, 'Self-compacting concrete incorporating steel and polypropylene fibers: Compressive and tensile strengths, moduli of elasticity and rupture, compressive stress-strain curve, and energy dissipated under compression', COMPOSITES PART B-ENGINEERING, vol. 53, no. 1, pp. 121-133.
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Fiber-reinforced self-compacting concrete (FRSCC) is a high-performance building material that combines positive aspects of fresh properties of self-compacting concrete (SCC) with improved characteristics of hardened concrete as a result of fiber addition. Considering these properties, the application ranges of both FRSCC and SCC can be covered. A test program is carried out to develop information about the mechanical properties of FRSCC. For this purpose, four SCC mixes - plain SCC, steel, polypropylene, and hybrid FRSCC - are considered in the test program. The properties include compressive and splitting tensile strengths, moduli of elasticity and rupture, compressive stress-strain curve, and energy dissipated under compression. These properties are tested at 3, 7, 14, 28, 56, and 91 days. Relationships are established to predict the compressive and splitting tensile strengths, moduli of elasticity and rupture, compressive stress-strain curve, and energy dissipated under compression. The models provide predictions matching the measurements. © 2013 Elsevier Ltd. All rights reserved.

Dackermann, U, Li, J & Samali, B 2013, 'Identification of member connectivity and mass changes on a two-storey framed structure using frequency response functions and artificial neural networks', JOURNAL OF SOUND AND VIBRATION, vol. 332, no. 16, pp. 3636-3653.
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This paper presents a structural health monitoring (SHM) technique that utilises pattern changes in frequency response functions (FRFs) as input parameters for a system of artificial neural networks (ANNs) to assess the structural condition of a structure. To verify the proposed method, it is applied to numerical and experimental models of a two-storey framed structure, on which structural damage is induced by member connectivity and mass changes, respectively. For the numerical structure, simulated time-history data are polluted with various levels of white Gaussian noise in order to realistically represent field-testing conditions. As a damage indicator, residual FRFs are used, which are derived by calculating the differences in FRF data between the undamaged/baseline structure and the structure with changed joint conditions or added mass. To obtain suitable patterns for neural network training, principal component analysis (PCA) techniques are adopted to reduce the size of the residual FRF data and to filter noise. A hierarchical system of individual ANNs, termed network ensemble, is then trained to map changes in PCA-reduced residual FRFs to damage conditions. The results obtained for both damage investigations, namely joint damage and mass changes, demonstrate that the proposed SHM technique is accurate and reliable in assessing the condition of the test structure numerically and experimentally based on direct FRF measurements and network ensemble analysis. From the outcomes of the individual networks, it is found that the proposed hierarchical network ensemble approach is highly efficient in filtering poor results of underperforming networks obtained from measurement locations with low damage sensitivity. © 2013 Elsevier Ltd.

Dackermann, U, Li, J, Rijal, R & Samali, B 2013, 'A Vibration-Based Approach for the Estimation of the Loss of Composite Action in Timber Composite Systems', STRUCTURAL HEALTH ASSESSMENT OF TIMBER STRUCTURES, vol. 778, pp. 462-469.
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This paper presents a novel approach for the determination of the loss of composite action for timber composite systems using only measurements from non-destructive vibration testing. Traditionally, the composite action of a system is evaluated from static load testing using deflection measurements. However, static load testing is expensive, time consuming and inappropriate for existing flooring systems. The method proposed in this paper is based on the Damage Index (DI) method, which uses changes in modal strain energies, to detect locations and severities of damage. In the proposed method, a new Loss of Composite Action Index (LCAI), which is derived from direct mode shape measurements obtained from dynamic testing, is introduced to evaluate the loss of composite action. The proposed method is tested and validated on numerical and experimental models of a timber composite beam structure, which consists of two timber components that are connected with different numbers of screws to simulate various degrees of partial composite states. The results obtained from the new method are very encouraging and show a clear trend of the proposed dynamic-based LCAI in indicating the loss of composite action in the investigated timber composite structure. © (2013) Trans Tech Publicutions, Switzerland.

Ding, G 2013, 'Demolish or refurbish – Environmental benefits of housing conservation', Construction Economics and Building, vol. 13, no. 2, pp. 18-34.
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Climate change and energy efficiency are some of the most pressing issues facing China today. With its economic growth since 1978, the government has struggled to contain environmental damages and social unrest related to the economy’s rapid transformation. With the rapid growth in population and urbanization the demand for housing has escalated and traditional housing has been under threat of demolition to make way for new construction. Traditional housing is generally considered wasteful in its use of land and/or energy, and is often demolished for more intensive and more energy-efficient housing, despite the resulting loss of embodied energy and urban amenity. A research project was undertaken to study the environmental performance of traditional housing in Hangzhou. The project looks into analyzing and comparing embodied energy and CO2 for seven dwellings. In addition indoor climate data were recorded and collected in the form of hourly temperature and humidity readings for one year in six local houses and in a modern unit as a control for one year. The research results reveal that there is little difference in environmental performance between traditional and conventional modern construction and the value of conservation rather than demolition as a strategic development for the construction industry.

Ding, G & Forsythe, PJ 2013, 'Sustainable construction: life cycle energy analysis of construction on sloping sites for residential buildings', Construction Management and Economics, vol. 31, no. 3, pp. 254-265.
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In 2010, the Australian residential construction sector contributed about 28% of the value of all construction and was responsible for 8% of the total energy consumption. Residential construction will continue to increase to cope with the demand due to population growth. Owing to land scarcity, construction on sloping sites has become a common construction method for residential development in Australia. This method has economic benefits but poses environmental issues as it damages topsoil, disturbs natural drainage and groundwater pathways and imposes additional stress on soil under fill. The life cycle energy consumption of the construction process is examined in relation to residential projects on sloping sites on a range of slopes and soil types in New South Wales, Australia. Forty-one detached dwellings were selected and a service life of 60 years assumed for the study. The research findings reveal that the slope for each type of soil has a positive correlation with life cycle energy consumption. As part of the onsite construction process, the results also show that the energy consumption of construction on sloping sites plays a significant factor in the life cycle energy analysis of a building. © 2013 Copyright Taylor and Francis Group, LLC.

Ding, GKC 2013, 'Strategies for sustainable housing development-the challenges from renewable energy', International Journal for Housing Science and Its Applications, vol. 37, no. 4, pp. 239-248.
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One-fifth of Australia's greenhouse gas emissions come from households. There are 7 million households in Australia and each is producing about 15 tonnes of greenhouse gas every year. Energy use, car use and waste are the largest sources of household emissions. Improving the energy efficiency of homes is one of the most effective ways of reducing greenhouse gas emissions and has been the main focus of the government's energy policy. In addition to the introduction of BASIX as mandatory to all new homes in NSW in 2004, the federal and state governments have introduced incentive schemes to subsidize Australian homes to install solar panels and other renewable energy technologies as a way to improve energy performance of existing homes since 2006. This paper examines the opportunities and challenges of renewable energy in improving energy efficiency of existing dwellings. The paper also presents the results of an economic analysis of renewable energy source in a dwelling in NSW. Finally a strategic direction of providing affordable and environmentally sustainable practices in upgrading existing homes to improve energy efficiency is also developed and discussed. Copyright © 2013 IAHS.

Dragos, J & Wu, C 2013, 'A new general approach to derive normalised pressure impulse curves', International Journal of Impact Engineering, vol. 62, pp. 1-12.
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Dragos, J, Wu, C & Oehlers, DJ 2013, 'Simplification of fully confined blasts for structural response analysis', Engineering Structures, vol. 56, pp. 312-326.
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Dragos, J, Wu, C & Vugts, K 2013, 'Pressure-Impulse Diagrams for an Elastic-Plastic Member under Confined Blasts', International Journal of Protective Structures, vol. 4, no. 2, pp. 143-162.
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Pressure-impulse (P-I) diagrams based on the equivalent single-degree-of-freedom approach (SDOF) have been used during building design in order to assess the effects of blasts on structures. They provide an easy way to describe the likely outcome of the combination of blast pressures and impulses on a particular structural element in a building at the moment an explosion occurs. However, only P-I diagrams of structural members under external blasts have been addressed in current guidelines and previous studies. Due to the complexity of confined scenarios, confined blast pressure-time histories cannot be approximated by simplified representations of pressure-time histories used for external blasts, such as triangular shapes representing linear decay or curves indicating exponential decay. Rather, they should be simplified as bilinear pressure-time histories. Thus, SDOF models which incorporate bilinear blast loads were developed to predict the response of a member with a bilinear, elastic-plastic-hardening, resistance-deflection function. Then using the developed SDOF model, normalised P-I Diagrams for structural members with bilinear resistance-deflection functions under bilinear blasts were generated. These results were then used to undertake a parametric study to investigate the influence of varying blast load shapes and varying bilinear resistance-deflection function shapes on the normalised P-I curves. Also, comparisons against other techniques employed to eliminate pulse load shape effects were also undertaken for bilinear pulse loads and bilinear resistance-deflection function shapes.

Dragos, J, Wu, C, Haskett, M & Oehlers, D 2013, 'Derivation of Normalized Pressure Impulse Curves for Flexural Ultra High Performance Concrete Slabs', Journal of Structural Engineering, vol. 139, no. 6, pp. 875-885.
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Duc, H, Azzi, M, Wahid, H & Ha, QP 2013, 'Background ozone level in the Sydney basin: assessment and trend analysis', INTERNATIONAL JOURNAL OF CLIMATOLOGY, vol. 33, no. 10, pp. 2298-2308.
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It has been recognized that the background ozone concentration in urban areas is changing over the years. This article aims to determine the background ozone level (BOL) using ambient air quality data measurements collected at some monitoring stations in the Sydney basin, Australia. A definition of background ozone in the context of the Sydney region is proposed. With this definition, it is possible to estimate the background ozone using ambient measurements of ozone and its precursors. The trend of the BOL is also estimated from the temporal ambient monitoring records as of early 1998-2005. These ozone level changes at different monitoring stations are assessed using the linear regression method. The results are shown to vary between different monitoring sites. This demonstrates that the local conditions at each site are important in determining as to whether an air quality management plan for reducing the ozone level to below the exceedance level is effective and achievable or not. Furthermore, the results obtained are compared with those obtained by the ClappJenkin method, which is based on the relationship between oxidant and nitrogen oxides, assuming a stationary state of photochemical smog function.

Elsener, R, Dackermann, U, Li, J, Samali, B & Crews, K 2013, 'Experimental Investigations of Material Properties of Timber Utility Poles using various Material Testing Approaches', STRUCTURAL HEALTH ASSESSMENT OF TIMBER STRUCTURES, vol. 778, pp. 265-272.
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Fatahi, B & Khabbaz, H 2013, 'Optimising the pattern of semi-rigid columns to improve performance of rail tracks overlying soft soil formation', Australian Geomechanics Journal, vol. 48, no. 3, pp. 89-97.
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With Australia facing a rapid increase in population in the next 30 years, the government is being proactive in handling the forecasted growth. The release of 2010 Metropolitan Transport Plan by the New South Wales (NSW) Government shows that the State of NSW will see an increase in commuter travel by rail. The NSW rail system is one of the most complex networks in the world and due to population growth, the network will require further expansion with construction of new railway lines partly on weak and marginal ground and will also require more frequent train running on existing lines. This study seeks to identify the effectiveness of semi-rigid inclusion ground improvement techniques particularly stone columns and deep soil mixing in controlling settlement of soft soils when placed under the dead loads of the rail structure and the large live loads of freight trains. The employed numerical study assesses the relationship between the column position in the track cross section and the overall settlement of the ballasted rail formation. The numerical results show that the overall settlement of the track reduces significantly with the use of columns close to the centre of the track and not just under the rail. In addition, application of one layer of geogrids between sub-ballast and sub-grade assists to reduce the maximum settlement of track decreasing the future maintenance costs.

Fatahi, B & Khabbaz, H 2013, 'PREDICTING SETTLEMENT OF CHEMICALLY STABILISED LANDFILLS', INTERNATIONAL JOURNAL OF GEOMATE, vol. 5, no. 10, pp. 700-705.

Fatahi, B, Fatahi, B, Le, TM & Khabbaz, H 2013, 'Small-strain properties of soft clay treated with fibre and cement', GEOSYNTHETICS INTERNATIONAL, vol. 20, no. 4, pp. 286-300.
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To improve the dynamic properties of soft soil, the cement treatment technique combined with fibre reinforcement can be employed. In this study, the effects of two types of fibres (polypropylene and recycled carpet) on the hardening process and small-strain properties of cement-treated kaolinite and bentonite clays are investigated. Cement-treated clay specimens were prepared using cement contents of 5%, 10% and 15% by weight of dry soil for the kaolinite samples, and 30%, 40% and 50% for the bentonite samples. To investigate and understand the influence of different fibre types and contents, three different percentages of fibre content were adopted: 0.1%, 0.2% and 0.5% polypropylene fibres, and 0.5%, 0.75% and 1% carpet fibres. The results of bender element tests on 126 cylindrical samples of cement-treated clay with various cement and fibre contents were analysed to discern the relationships between fibre and cement content and the small-strain mechanical properties, including the shear wave velocity and maximum small-strain shear modulus of the treated soil. The influence of fibres and cement contents on the hardening time of treated soil has also been investigated. © 2013 Thomas Telford Ltd.

Fatahi, B, Le, TM, Fatahi, B & Khabbaz, H 2013, 'Shrinkage Properties of Soft Clay Treated with Cement and Geofibers', Geotechnical and Geological Engineering, vol. 31, no. 5, pp. 1421-1435.
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In this study, effects of two types of geofibers, namely polypropylene and recycled carpet, on three dimensional shrinkage properties of cement treated kaolinite and bentonite clays are investigated. Cement treated clay specimens were prepared with cement contents of 5, 10, and 15 % by weight of dry soil for kaolinite samples, and 30, 40 and 50 % for bentonite samples. To investigate and understand the influence of different fiber types and contents, three different percentages of fiber content (i.e. 0.1, 0.2 and 0.5 % polypropylene fibers; and 0.5, 0.75 and 1 % carpet fibers) were adopted. The results of shrinkage tests on 126 cylindrical samples of cement treated clay with various cement and fiber contents were analysed to understand the relationships between these parameters and the shrinkage percentage of treated soil. Results of this study indicate that combination of cement and fiber is effective in reducing the volume change of clayey soils undergoing drying process. In the applied ranges of cement and fiber contents, the influence of cement addition on the shrinkage reduction is more significant than the addition of fibers for the treated kaolinite. However, addition of fibers in curtailing the shrinkage of bentonite clay is more significant than the cement addition. © 2013 Springer Science+Business Media Dordrecht.

Fatahi, B, Le, TM, Le, MQ & Khabbaz, H 2013, 'Soil creep effects on ground lateral deformation and pore water pressure under embankments', Geomechanics and Geoengineering, vol. 8, no. 2, pp. 107-124.
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Analysing the behaviour of the soft ground under embankments is a challenging task and is of significant interest to practising geotechnical engineers. This paper revisits a well known case study of an embankment of Boston Blue Clay, which was thoroughly instrumented and measured with piezometers, settlement rods and inclinometers over a long time period during and after construction. The soil parameters were very comprehensively collected by both in situ and laboratory tests in several major test programs. The behaviour of the ground considering the modified Cam-Clay model including and excluding soil creep is simulated using finite element method. The analysed data are verified with field measurements and a parametric study is conducted to evaluate the influence of creep index on excess pore water pressures generated and the displacement of the ground under the embankment. It is observed that both horizontal displacements and excess pore water pressures of the ground under the embankment increased by the creep index. Thus effects of soil creep should be precisely considered in predicting the ground performance under embankments. © 2013 Copyright Taylor and Francis Group, LLC.

Ha, QP, Nguyen, MT, Li, J & Kwok, NM 2013, 'Smart Structures With Current-Driven MR Dampers: Modeling and Second-Order Sliding Mode Control', IEEE-ASME TRANSACTIONS ON MECHATRONICS, vol. 18, no. 6, pp. 1702-1712.
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Smart structures are civil or mechanical structures that can automatically and intelligently react to external dynamic loadings such as vibration shocks, strong winds, destructive waves, and earthquakes. The use of magnetorheological (MR) dampers has been of increasing interest in smart structures as they have reliable, stable and fail-safe operations, small energy requirements, and fast responses. The challenges of MR damper structural control rest with the complex dynamics involved, high nonlinearity due to the force-velocity hysteresis, nonaffinity, and constraints of the control system with the magnetization current as its input. To address these problems, this paper presents the modeling and control design as well as the implementation results of a second-order sliding mode controller for the MR dampers embedded in the building structures subject to quake-induced vibrations. Based on the static hysteresis model of the MR damper using computationally tractable algebraic expressions, algorithms are proposed to control directly the magnetization current to the dampers, configured in a differential mode to counteract the offset force. The effectiveness of the proposed technique is verified in simulation by using a building model under quake-like excitations. The experimental results are provided on a laboratorial setup tested on a shake table. © 2013 IEEE.

Hu, H, Jiang, X, Li, Y, Wang, J & Qian, S 2013, 'Integrated design and controllability test of piezoelectric self-powered MR absorber', Zhendong Ceshi Yu Zhenduan/Journal of Vibration, Measurement and Diagnosis, vol. 33, no. 4, pp. 712-718.
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Aiming at the piezoelectric self-powered MR absorber, the feasibility of structure composite and function integration is studied, by combining the semi-active vibration control device based on MR technology with energy harvesting equipment based on piezoelectric vibrator. A theory model of piezoelectric self-powered MR absorber is established. Then, its magnetic circuit structure of MR absorber is optimized and designed by using the numerical simulation method, its influences of piezoelectric vibrator's geometric parameters on the outputting voltage of the vibration energy harvesting equipment are also analyzed, and the vibration energy harvesting circuit is simulated and tested, respectively. The simulation results show that the current of 1.67 A could be provided into the coil of MR absorber once the ring-shaped piezoelectric vibrator is excited by AC voltage source. Finally, an experimental platform is constructed in order to test its controllability of the piezoelectric self-powered MR absorber. The experimental results show that the ring-shaped piezoelectric vibrator could provide an enough amount of electrical energy for the piezoelectric self-powered MR absorber's semi-active vibration control, and its damping force achieves 2.4 times before and after the on-off controlling strategy.

Indraratna, B & Nimbalkar, S 2013, 'Closure to “Stress-Strain Degradation Response of Railway Ballast Stabilized with Geosynthetics” by Buddhima Indraratna and Sanjay Nimbalkar', Journal of Geotechnical and Geoenvironmental Engineering, vol. 139, no. 12, pp. 2233-2233.
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Indraratna, B & Nimbalkar, S 2013, 'Stress-Strain Degradation Response of Railway Ballast Stabilized with Geosynthetics', Journal of Geotechnical and Geoenvironmental Engineering, vol. 139, no. 5, pp. 684-700.
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Indraratna, B, Nimbalkar, S & Rujikiatkamjorn, C 2013, 'Modernisation of Rail Tracks for Higher Speeds and Greater Freight', International Journal of Railway Technology, vol. 2, no. 3, pp. 1-20.
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INDRARATNA, B, TENNAKOON, N, NIMBALKAR, S & RUJIKIATKAMJORN, C 2013, 'Behaviour of clay-fouled ballast under drained triaxial testing', Géotechnique, vol. 63, no. 5, pp. 410-419.
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Contamination or fouling of rail ballast with external fines, including slurried and pumped subgrade material (e.g. clay and silt), is one of the primary reasons for track deterioration. Fouling causes differential settlement of the track, and also decreases the load-bearing capacity, owing to the reduction in the friction angle of the granular assembly. In certain circumstances, fouled ballast needs to be cleaned or replaced to maintain the desired track stiffness, load-bearing capacity and track alignment, all of which influence safety. This paper presents and discusses the results of a series of large-scale triaxial tests conducted on latite basalt, a rail ballast of volcanic origin, commonly used in Australia. Consolidated drained triaxial tests were conducted under three different levels of confining pressure and varying degrees of clay fouling. Stress–strain degradation characteristics are discussed in detail. This paper also describes the non-linear strength envelope and a novel empirical relationship to capture the detrimental effects of clay fouling on the performance of ballasted tracks.

Khorsandnia, N, Valipour, HR & Crews, K 2013, 'Nonlinear finite element analysis of timber beams and joints using the layered approach and hypoelastic constitutive law', ENGINEERING STRUCTURES, vol. 46, no. 1, pp. 606-614.
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This paper focuses on development and application of finite element models for nonlinear analysis of timber, timberâconcrete composite (TCC) beams and joints. A new piecewise continuous orthotropic failure envelope in the bi-axial stress space is proposed for modelling timber behaviour. The proposed orthotropic surface is simplified based on isotropic behaviour of timber along the grains and the model is formulated within the framework of hypoelastic constitutive law. The developed constitutive law and finite element (FE) models are verified by examples taken from the literature including timber beams with and without notches and holes subject to three- and four-point bending as well as push-out test results of TCC connections. Further, the accuracy and performance of the proposed constitutive law for capturing nonlinear behaviour and failure load of timber beams and connections is compared with orthotropic Hashin damage model. The FE results show good agreement with experimental results in terms of loadâdisplacement response and ultimate loading capacity of members and it is concluded that the developed timber model can adequately capture the global as well as the local behaviour of timber beams and TCC connections.

Langston, C 2013, 'The role of coordinate-based decision-making in the evaluation of sustainable built environments', Construction Management and Economics, vol. 31, no. 1, pp. 62-77.
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Existing environmental performance assessment approaches focus on the overall performance to reflect sustainability of built projects. However, the impacts caused by construction activities on the environment occur throughout a project's life cycle which may be different at different stages. Similarly, the economic benefits and social impacts from implementing a construction project may be different in different project stages. This paper presents a model of the sustainable development value (SDV), which integrates sustainability assessment into the building process. SDV measures the significance of the concerned project to the attainment of sustainable development values at different stages of a building life cycle, and the SDV at each stage will be amalgamated into the model of sustainable development ability (SDA). SDA is used as a prototype to demonstrate the extent of sustainable performance to aid decision making. This paper presents the methodological framework of SDV and SDA, and the implementation was demonstrated using a case study.

Li, J & Hao, H 2013, 'Numerical study of structural progressive collapse using substructure technique', Engineering Structures, vol. 52, pp. 101-113.
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During their service life, modern structures may experience extreme loading conditions. Large loads generated from bomb explosion may have catastrophic consequences with a large number of casualties as well as great economical loss. Ever since the terrorist attack of 2001, great safety concerns have been raised for urban areas where more and more high-rise buildings have been erected and thus are more prone to suffer the potential threat. Among all the structural responses to blast loads, the catastrophic progressive collapse has attracted great attention around the world. Experimental studies on this topic are not only expensive but also are often prohibited due to safety concerns. With the advancement of computational mechanics techniques and computer power, reliable computer simulations of structural response and collapse to blast loads become possible. However, even with modern computer power, such computer simulations are still extremely time and resource consuming. In this paper, a new numerical approach that incorporates static condensation into the FE model is presented to simulate blast load induced structural response and progressive collapse. Two 6-story RC frame buildings are used as examples to demonstrate the efficiency of the proposed method. For comparison, direct finite element modeling of the same example frame structure is also carried out. Comparing the results from both approaches, it is found that the proposed method is efficient and reliable in simulating the structural response and progressive collapse with substantially less computational effort as compared to the direct FE model simulations. © 2013 Elsevier Ltd.

Li, Y, Li, J & Samali, B 2013, 'On the magnetic field and temperature monitoring of a solenoid coil for a novel magnetorheological elastomer base isolator', 13TH INTERNATIONAL CONFERENCE ON ELECTRORHEOLOGICAL FLUIDS AND MAGNETORHEOLOGICAL SUSPENSIONS (ERMR2012), vol. 412, no. 1, pp. 1-7.
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Following a successful experimental validation of a magnetorheological elastomer (MRE) base isolator, this study presents one of the major concerns, the heating of the magnetic coil, in the design and development of the adaptive MRE based isolator. In this research, the MRE materials, with a total thickness of nearly 150 mm, are placed as the magnetic core of the device to best utilize the magnetic energy provided by the coil. A series of tests are undertaken to investigate the magnetic fields inside the coil with or without the MRE materials. Thermocouples are used to monitoring the surface temperature of the coil when it is applied with various currents for 10 min. It is shown that the measurement of field inside the solenoid when no MRE is placed inside agrees with the theoretical analysis. It is also shown that the temperature of the coil increase dramatically when a current is applied. Cooling of the coil may takes even longer, about 4 h, till down to the room temperature. Dropping of the magnetic field is observed when the temperature goes high. © Published under licence by IOP Publishing Ltd.

Li, Y, Li, J, Li, W & Samali, B 2013, 'Development and characterization of a magnetorheological elastomer based adaptive seismic isolator', SMART MATERIALS AND STRUCTURES, vol. 22, no. 3, pp. 1-12.
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One of the main shortcomings in current base isolation design/practice is lack of adaptability. As a result, a base isolation system that is effective for one type earthquake may become ineffective or may have adverse effect for other earthquakes. The vulnerability of traditional base isolation systems can be exaggerated by two types of earthquakes, i.e. near-field earthquakes and far-field earthquakes. This paper addresses the challenge facing current base isolation design/practice by proposing a new type of seismic isolator for the base isolation system, namely an adaptive seismic isolator. The novel adaptive seismic isolator utilizes magnetorheological elastomer (MRE) for its field-sensitive material property. Traditional seismic isolator design with a unique laminated structure of steel and MRE layers has been adopted in the novel MRE seismic isolator. To evaluate and characterize the behavior of the MRE seismic isolator, experimental testing was conducted on a shake table facility under harmonic cycling loading. Experimental results show that the proposed adaptive seismic isolator can successfully alter the lateral stiffness and damping force in real time up to 37% and 45% respectively. Based on the successful development of the novel adaptive seismic isolator, a discussion is also extended to the impact and potential applications of such a device in structural control applications in civil engineering. © 2013 IOP Publishing Ltd.

Li, Y, Li, J, Tian, T & Li, W 2013, 'A highly adjustable magnetorheological elastomer base isolator for applications of real-time adaptive control', SMART MATERIALS AND STRUCTURES, vol. 22, no. 9, pp. 1-18.
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Inspired by its controllable and field-dependent stiffness/damping properties, there has been increasing research and development of magnetorheological elastomer (MRE) for mitigation of unwanted structural or machinery vibrations using MRE isolators or absorbers. Recently, a breakthrough pilot research on the development of a highly innovative prototype adaptive MRE base isolator, with the ability for real-time adaptive control of base isolated structures against various types of earthquakes including near- or far-fault earthquakes, has been reported by the authors. As a further effort to improve the proposed MRE adaptive base isolator and to address some of the shortcomings and challenges, this paper presents systematic investigations on the development of a new highly adjustable MRE base isolator, including experimental testing and characterization of the new isolator. A soft MR elastomer has been designed, fabricated and incorporated in the laminated structure of the new MRE base isolator, which aims to obtain a highly adjustable shear modulus under a medium level of magnetic field. Comprehensive static and dynamic testing was conducted on this new adaptive MRE base isolator to examine its characteristics and evaluate its performance. The experimental results show that this new MRE base isolator can remarkably change the lateral stiffness of the isolator up to 1630% under a medium level of magnetic field. Such highly adjustable MRE base isolator makes the design and implementation of truly real-time adaptive (e.g. semi-active or smart passive) seismic isolation systems become feasible. © 2013 IOP Publishing Ltd.

Liu, B, Ray, A & Thomas, PS 2013, 'Investigation of autoclaved cement systems with reactive MgO and Al₂O₃-SiO₂ rich fired clay brick', Advances in Cement Research, vol. 25, no. 5, pp. 281-287.
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Portland cement (PC) is one of the world's most important building materials, as it is a fundamental component of concrete. However, the manufacture of PC is highly energy intensive and leads to the emission of carbon dioxide (CO2). One promising control measure is the use of industrial wastes and by-products as supplementary cementing materials (SCMs) in order to minimise PC consumption, thereby producing greener cement-based products. This study investigates mechanical properties and phase development of hydrothermally treated cement–ground quartz sand blends with the incorporation of fired clay-brick (CB) waste and reactive magnesia (MgO). The addition of CB waste in autoclaved PC–quartz mortar mixes showed that the alumina–silica rich CB waste was pozzolanic when the Al2O3 accelerated formation and increased crystallinity of Al substituted 1·1 nm tobermorite, resulting in the observed strength gain. Autoclaved mortar specimens incorporating reactive MgO showed a reduction in strength with increasing MgO addition. This was a result of dilution when the relative proportion of PC available for the formation of the strength contributing hydration products including tobermorite is decreased.

Liu, J, Ding, GKC & Samali, B 2013, 'Building Sustainable Score (BSS)—A Hybrid Process Approach for Sustainable Building Assessment in China', Journal of Power and Energy Engineering, vol. 01, no. 05, pp. 58-62.
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Sustainable building in China has gained attention both domestically and abroad. Despite the fast increase in sustainable assessment tools developed locally or adopted from overseas, there are still criticisms about the current situation of weak implementation and lack of comprehensive consideration. The lack of consideration of economic and social as-pects or building performance on whole building life cycle all lead to departure from the true meaning of sustainable development. And lack of participation on the part of stakeholders makes it too theoretical to be carried out. This re-search aims to develop a model to address this problem. This research started with review of current sustainable as-sessment tools applied in China. As the assessment indicators have clear regional disparities, and almost no current tool considers all three pillars of environmental, economic and social in building life cycle. An industry survey was therefore designed for generation of indicators at different building stages, and personal interviews relevant to different occupa-tion in building industry were conducted to complement the questionnaire survey. After that, the model Building Sus-tainable Score (BSS) was developed based on the stakeholders participation. Finally, the model is verified by a case study.

Lu, Y, Li, J, Ye, L & Wang, D 2013, 'Guided waves for damage detection in rebar-reinforced concrete beams', Construction and Building Materials, vol. 47, no. 1, pp. 370-378.
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The propagation properties of ultrasonic waves in rebar-reinforced concrete beams were investigated for the purpose of damage detection. Two types of piezoelectric (PZT) elements were used in experiments in which PZT disks were attached on the surfaces of concrete beams to observe wave propagation in concrete before and after a four-point bending test, while rectangular PZT patches were attached at the exposed ends of the rebar to monitor wave transmission along the rebar with and without simulated corrosion in the form of partial material removal from the rebar. Experimental testing demonstrated that the surface-attached PZT disks were capable of detecting the change in material properties due to the existence of cracking. In consideration of the inevitable discrepancies in different concrete beams due to specimen preparation and sensor installation, principal component analysis based on statistical parameters extracted from wave signals was applied to highlight the difference between benchmark and damaged rebar. The results show the potential of the principal components as damage indices for quantifying integrity conditions of concrete structures.

Noushini, A, Samali, B & Vessalas, K 2013, 'Effect of polyvinyl alcohol (PVA) fibre on dynamic and material properties of fibre reinforced concrete', CONSTRUCTION AND BUILDING MATERIALS, vol. 49, no. 1, pp. 374-383.
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The effect of uncoated polyvinyl alcohol (PVA) fibre addition on dynamic properties of fibre reinforced concrete (FRC) has been investigated in the current study. PVA fibres of two geometric lengths (6 and 12 mm) with aspect ratio of 428 and 857, respectively, were utilised. Fly ash was also used as partial replacement of Portland cement in all mixes. Based on total concrete volume, two fibre fractions of 0.25% and 0.5% were evaluated for their effect on fundamental frequency, dynamic modulus of elasticity and damping ratio of FRC. 28-Day static mechanical properties are also measured. From the results, it can be stated that although PVA fibre addition in low volume fractions used in this study significantly enhance the mechanical properties of FRC, it has no considerable effect on concrete material damping characteristics. © 2013 Elsevier Ltd. All rights reserved.

Subhani, M, Li, J & Samali, B 2013, 'A comparative study of guided wave propagation in timber poles with isotropic and transversely isotropic material models', Journal of Civil Structural Health Monitoring, vol. 3, no. 2, pp. 65-79.
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Subhani, M, Li, J, Samali, B & Yan, N 2013, 'Determination of the embedded lengths of electricity timber poles utilising flexural wave generated from impacts', Australian Journal of Structural Engineering, vol. 14, no. 1, pp. 85-96.
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Round timbers are extensively used as utility poles in Australia for electricity distribution and communication. Lack of information on their conditions results in great difficulties on asset management for industries. Despite the development of various

Subhani, M, Li, JC, Gravenkamp, H & Samali, B 2013, 'Effect of Elastic Modulus and Poisson's Ratio on Guided Wave Dispersion Using Transversely Isotropic Material Modelling', Advanced Materials Research, vol. 778, pp. 303-311.
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Timber poles are commonly used for telecommunication and power distribution networks, wharves or jetties, piling or as a substructure of short span bridges. Most of the available techniques currently used for non-destructive testing (NDT) of timber structures are based on one-dimensional wave theory. If it is essential to detect small sized damage, it becomes necessary to consider guided wave (GW) propagation as the behaviour of different propagating modes cannot be represented by one-dimensional approximations. However, due to the orthotropic material properties of timber, the modelling of guided waves can be complex. No analytical solution can be found for plotting dispersion curves for orthotropic thick cylindrical waveguides even though very few literatures can be found on the theory of GW for anisotropic cylindrical waveguide. In addition, purely numerical approaches are available for solving these curves. In this paper, dispersion curves for orthotropic cylinders are computed using the scaled boundary finite element method (SBFEM) and compared with an isotropic material model to indicate the importance of considering timber as an anisotropic material. Moreover, some simplification is made on orthotropic behaviour of timber to make it transversely isotropic due to the fact that, analytical approaches for transversely isotropic cylinder are widely available in the literature. Also, the applicability of considering timber as a transversely isotropic material is discussed. As an orthotropic material, most material testing results of timber found in the literature include 9 elastic constants (three elastic moduli and six Poisson's ratios), hence it is essential to select the appropriate material properties for transversely isotropic material which includes only 5 elastic constants. Therefore, comparison between orthotropic and transversely isotropic material model is also presented in this article to reveal the effect of elastic moduli and Pois...

Tabatabaiefar, SHR, Fatahi, B & Samali, B 2013, 'Lateral seismic response of building frames considering dynamic soil-structure interaction effects', STRUCTURAL ENGINEERING AND MECHANICS, vol. 45, no. 3, pp. 311-321.
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In this study, to have a better judgment on the structural performance, the effects of dynamic Soil-Structure Interaction (SSI) on seismic behaviour and lateral structural response of mid-rise moment resisting building frames are studied using Finite Difference Method. Three types of mid-rise structures, including 5, 10, and 15 storey buildings are selected in conjunction with three soil types with the shear wave velocities less than 600m/s, representing soil classes Ce, De and Ee, according to Australian Standard AS 1170.4. The above mentioned frames have been analysed under two different boundary conditions: (i) fixed-base (no soil-structure interaction), and (ii) flexible-base (considering soil-structure interaction). The results of the analyses in terms of structural lateral displacements and drifts for the above mentioned boundary conditions have been compared and discussed. It is concluded that the dynamic soil-structure interaction plays a considerable role in seismic behaviour of mid-rise building frames including substantial increase in the lateral deflections and inter-storey drifts and changing the performance level of the structures from life safe to near collapse or total collapse. Thus, considering soil-structure interaction effects in the seismic design of mid-rise moment resisting building frames, particularly when resting on soft soil deposit, is essential.

Tabatabaiefar, SHR, Fatahi, B & Samali, B 2013, 'Seismic Behavior of Building Frames Considering Dynamic Soil-Structure Interaction', INTERNATIONAL JOURNAL OF GEOMECHANICS, vol. 13, no. 4, pp. 409-420.
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The seismic excitation experienced by structures is a function of the earthquake source, travel path effects, local site effects, and soilstructure interaction (SSI) influences. The result of the first three of these factors is referred to as free-field ground motion. The structural response to free-field motion is influenced by the SSI. In particular, accelerations within structures are affected by the flexibility of the foundation support and variations between the foundation and free-field motions. Consequently, an accurate assessment of inertial forces and displacements in structures can require a rational treatment of SSI effects. In the current study, to depict these effects on the seismic response of moment-resisting building frames, a 10-story moment-resisting building frame resting on a shallow foundation was selected in conjunction with three soil types with shear-wave velocities of less than 600 m/s, representing Soil Classes Ce, De, and Ee according to an existing Australian Standard. The structural sections were designed after applying dynamic nonlinear time-history analysis, based on both the elastic method, and inelastic procedure using the elastic-perfectly plastic behavior of the structural elements. The frame sections were modeled and analyzed using the finite-difference method andthe FLAC 2D software under two different boundary conditions: (1) fixed-base (no SSI) and (2) considering the SSI. Fully nonlinear dynamic analysis under the influence of various earthquake records was conducted and the results of the two different cases for elastic and inelastic behavior of the structuralmodel were extracted, compared, and discussed. The results indicate that the performance level of themodel resting on Soil Class Ce does not change substantially and remains in the life safe level while the performance level of themodel resting on Soil Classes De and Ee substantially increase from the life safe level to near collapse for both elastic and ine...

Tao, M, Li, X & Wu, C 2013, '3D numerical model for dynamic loading-induced multiple fracture zones around underground cavity faces', Computers and Geotechnics, vol. 54, pp. 33-45.
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Thomas, D, Ding, G & Crews, K 2013, 'Sustainable timber use in the Australian housing market: Are consumers willing to pay the price', International Journal for Housing Science and Its Applications, vol. 37, no. 3, pp. 187-196.
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A large proportion of traditional Australian homes contained timber floors and timber exterior cladding until the advent of the standard concrete slab/brick veneer house. Up to 95% of new homes are built by project home companies and the majority of these contain an external envelope consisting of concrete flooring, clay brick walls and concrete tile or steel sheet roofing. This design is currently driven by consumer's expectation of low cost, durable homes that are completed within restricted time limits. There is now a price premium on bespoke housing projects that differ materially or otherwise from a limited set of designs offered by project home firms. The adoption of concrete and brick homes originated from a perceived advantage of longevity, low maintenance and thermal comfort. Innovation in wood treatments, wood protection and insulation has provided solutions to these issues so that timber is now a viable option with added benefits such as environmental sustainability and erection speed. Australian consumers have a growing awareness and desire to live in a way that is sustainable and are making choices that reflect this attitude. This has been demonstrated through the high adoption rate of recent government-supported schemes such as subsidized insulation and solar panel installation. This paper aims at investigating homeowner's perception of timber as a sustainable building product, the desire of homeowners to use sustainable building products, and the willingness of homeowners to pay a premium to live sustainably. This paper highlights Australian homeowners reluctance to use the most sustainable building materials even when they are willing to pay for a more environmentally sustainable home. This paper presents the results of a questionnaire survey to homeowners in the city of Sydney, New South Wales, Australia and some strategies on how to increase the use of timber in new housing projects in Australia. © 2013 IAHS.

Thomas, PS, Guerbois, J-P & Smallwood, A 2013, 'Low temperature DSC characterisation of water in opal', Journal of Thermal Analysis and Calorimetry, vol. 113, no. 3, pp. 1255-1260.
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A low temperature (-60 to +105 A degrees C) DSC characterisation of opal was carried out to determine the proportion of crystallisable water and to estimate the cavity size in which the crystallisable water is contained. Circa 10 % of the molecular water

Visintin, P, Oehlers, DJ, Haskett, M & Wu, C 2013, 'Mechanics-Based Hinge Analysis for Reinforced Concrete Columns', Journal of Structural Engineering, vol. 139, no. 11, pp. 1973-1980.
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Visintin, P, Oehlers, DJ, Muhamad, R & Wu, C 2013, 'Partial-interaction short term serviceability deflection of RC beams', Engineering Structures, vol. 56, pp. 993-1006.
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Wahid, H, Ha, QP, Duc, H & Azzi, M 2013, 'Neural network-based meta-modelling approach for estimating spatial distribution of air pollutant levels', APPLIED SOFT COMPUTING, vol. 13, no. 10, pp. 4087-4096.
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Continuous measurements of the air pollutant concentrations at monitoring stations serve as a reliable basis for air quality regulations. Their availability is however limited only at locations of interest. In most situations, the spatial distribution beyond these locations still remains uncertain as it is highly influenced by other factors such as emission sources, meteorological effects, dispersion and topographical conditions. To overcome this issue, a larger number of monitoring stations could be installed, but it would involve a high investment cost. An alternative solution is via the use of a deterministic air quality model (DAQM), which is mostly adopted by regulatory authorities for prediction in the temporal and spatial domain as well as for policy scenario development. Nevertheless, the results obtained from a model are subject to some uncertainties and it requires, in general, a significant computation time. In this work, a meta-modelling approach based on neural network evaluation is proposed to improve the estimated spatial distribution of the pollutant concentrations. From a dispersion model, it is suggested that the spatially-distributed pollutant levels (i.e. ozone, in this study) across a region under consideration is a function of the grid coordinates, topographical information, solar radiation and the pollutant's precursor emission. Initially, for training the model, the input-output relationship is extracted from a photochemical dispersion model called The Air Pollution Model and Chemical Transport Model (TAPM-CTM), and some of those input-output data are correlated with the ambient measurements collected at monitoring stations. Here, improved radial basis function networks, incorporating a proposed technique for selection of the network centres, will be developed and trained by using the data obtained and the forward selection approach. The methodology is then applied to estimate the ozone concentrations in the Sydney basin, Austral...

Wu, C & Sheikh, H 2013, 'A finite element modelling to investigate the mitigation of blast effects on reinforced concrete panel using foam cladding', International Journal of Impact Engineering, vol. 55, pp. 24-33.
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Wu, C, Lukaszewicz, M, Schebella, K & Antanovskii, L 2013, 'Experimental and numerical investigation of confined explosion in a blast chamber', Journal of Loss Prevention in the Process Industries, vol. 26, no. 4, pp. 737-750.
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An experimental blast program consisting of four tests was conducted in a blast chamber to investigate the effects of cylindrical charges on the peak reflected overpressure and impulse on the wall of the chamber. The charge mass varied from 0.095 kg to 0.2 kg and the standoff distance remained constant at 1.5 m and 1.3 m for the axial and radial directions, respectively. Eight pressure transducers were used in each test to measure the reflected overpressures on confined chamber walls at key locations. A high speed camera was used to record footage of each blast event. The test results indicated that UFC-3-340-02 (Unified Facilities Criteria, 2008) gives a significantly lower prediction for the axially oriented cylindrical charge, and also underestimates the radially oriented cylinder. Another purpose of the blast program was to develop an experimental data set which would validate the AUTODYN model. This would enable the validated AUTODYN model to be used with confidence to generate the overpressure and impulse distribution on a structural element for varying parameters such as the charge shape and charge orientations. Based on the simulated results a new blast model for cylindrical charges has been proposed by considering blast loading on the same level as the charge across the longitudinal direction. © 2013 Elsevier Ltd.

Xiao, J, Li, W, Corr, DJ & Shah, SP 2013, 'Effects of interfacial transition zones on the stress–strain behavior of modeled recycled aggregate concrete', Cement and Concrete Research, vol. 52, pp. 82-99.
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Based on nanoindentation tests and analysis, the constitutive relationship of the Interfacial Transition Zones (ITZs) in Recycled Aggregate Concrete (RAC) is put forward. Together with the meso/micro-scale mechanical properties of each phase in Modeled Recycled Aggregate Concrete (MRAC), the plastic-damage constitutive models are employed in numerical studies on MRAC under uniaxial compression and uniaxial tension loadings to predict the overall mechanical behavior, particularly the stress-strain relationship. After the calibration and validation with the experimental results, a parametric study has been undertaken to analyze the effects of ITZs and new mortar matrix on the stress-strain relationship of MRAC. It is revealed that the mechanical properties of new mortar matrix and relative mechanical properties between ITZs and mortar matrices play a significant role in the overall stress-strain relationship and failure patterns of MRAC under both uniaxial compression and uniaxial tension loadings. © 2013 Elsevier Ltd. All rights reserved.

Xiao, J, Li, W, Corr, DJ & Shah, SP 2013, 'Simulation Study on the Stress Distribution in Modeled Recycled Aggregate Concrete under Uniaxial Compression', Journal of Materials in Civil Engineering, vol. 25, no. 4, pp. 504-518.
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To investigate the stress distribution in recycled aggregate concrete (RAC) under uniaxial compression, modeled recycled aggregate concrete (MRAC) was studied by numerical simulation. The mechanical properties of interfacial transition zones (ITZs) of RAC were measured by the nanoindentation technique. A two-dimensional numerical study of the stress distribution characteristics of MRAC under the uniaxial compression is presented. The simulation was verified by experimental results. A parametric analysis is then conducted to study the sensitivity of each phase's mechanical properties and the amounts of old cement mortar in the MRAC. Simulation results demonstrate that a concentration of tensile stress and shear stress appears around new and old ITZ regions. It is found that when the elastic modulus of natural aggregates increases, the magnitude of tensile stress concentration becomes higher, whereas as the elastic modulus of ITZs increases, the magnitude of stress concentration decreases. It is also shown that the higher relative elastic modulus of new cement mortar compared with that of the old cement mortar significantly reduces the stress concentrations at the regions between recycled coarse aggregate particles. The amount of old cement mortar affects the stress distribution in the new ITZ much more obviously than that in the old ITZ. © 2013 American Society of Civil Engineers.

Xiao, J, Li, W, Sun, Z, Lange, DA & Shah, SP 2013, 'Properties of interfacial transition zones in recycled aggregate concrete tested by nanoindentation', Cement and Concrete Composites, vol. 37, no. 1, pp. 276-292.
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The properties of new Interfacial Transition Zone (ITZ) and old ITZ in Recycled Aggregate Concrete (RAC) were investigated by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and nanoindentation. From the SEM images, obvious voids and high concentration of calcium hydroxide can be found in both old ITZ and new ITZ in RAC. Based on the nanoindentation study, it is indicated that the thicknesses of old and new ITZs are in the range 40-50 μm and in the range 55-65 μm, respectively. It is also found that the average indentation modulus of old ITZ is 70-80% of that of old paste matrix, while the average indentation modulus of new ITZ is 80-90% of that of new paste matrix. Additionally, the influences of mix proportion, aggregate types and hydration age on the properties of ITZs in RAC are discussed in this study.© 2012 Elsevier Ltd. All rights reserved.

Yang, J, Du, H, Li, W, Li, Y, Li, J, Sun, S & Deng, HX 2013, 'Experimental study and modeling of a novel magnetorheological elastomer isolator', SMART MATERIALS AND STRUCTURES, vol. 22, no. 11, pp. 1-14.
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This paper reports an experimental setup aiming at evaluating the performance of a newly designed magnetorheological elastomer (MRE) seismic isolator. As a further effort to explore the field-dependent stiffness/damping properties of the MRE isolator, a series of experimental testing were conducted. Based upon the analysis of the experimental responses and the characteristics of the MRE isolator, a new model that is capable of reproducing the unique MRE isolator dynamics behaviors is proposed. The validation results verify the model's effectiveness to portray the MRE isolator. A study on the field-dependent parameters is then provided to make the model valid with fluctuating magnetic fields. To fully explore the mechanism of the proposed model, an investigation relating the dependence of the proposed model on every parameter is carried out. © 2013 IOP Publishing Ltd.

Zeng, J, Guo, Y, Li, Y, Zhu, J & Li, J 2013, 'Two-dimensional magnetic property measurement for magneto-rheological elastomer', JOURNAL OF APPLIED PHYSICS, vol. 113, no. 17.
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Zhang, J, Xu, YL, Li, J, Xia, Y & Li, JC 2013, 'Statistical moment-based structural damage detection method in time domain', Earthquake Engineering and Engineering Vibration, vol. 12, no. 1, pp. 13-23.
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A novel structural damage detection method with a new damage index, i.e., the statistical moment-based damage detection (SMBDD) method in the frequency domain, has been recently proposed. The aim of this study is to extend the SMBDD method in the frequency domain to the time domain for building structures subjected to non-Gaussian and non-stationary excitations. The applicability and effectiveness of the SMBDD method in the time domainis verified both numerically and experimentally. Shear buildings with various damage scenarios are fi rst numerically investigated in the time domain taking into account the effect of measurement noise. The applicability of the proposed method in the time domain to building structures subjected to non-Gaussian and non-stationary excitations is then experimentally investigated through a series of shaking table tests, in which two three-story shear building models with four damage scenarios aretested. The identifi ed damage locations and severities are then compared with the preset values. The comparative results are found to be satisfactory, and the SMBDD method is shown to be feasible and effective for building structures subjected to non-Gaussian and non-stationary excitations.

Askari, M, Li, J & Samali, B 1970, 'A Multi-objective Subtractive FCM Based TSK Fuzzy System with Input Selection, and Its Application to Dynamic Inverse Modelling of MR Dampers', Lecture Notes in Computer Science, International Conference on Artificial Intelligence and Soft Computing, Springer Berlin Heidelberg, Zakopane, POLAND, pp. 215-226.
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A new encoding scheme is presented for a fuzzy-based nonlinear system identification methodology, using the subtractive Fuzzy C-Mean clustering and a modified version of non-dominated sorting genetic algorithm. This method is able to automatically select the best inputs as well as the structure of the fuzzy model such as rules and membership functions. Moreover, three objective functions are considered to satisfy both accuracy and compactness of the model. The proposed method is then employed to identify the inverse model of a highly nonlinear structural control device, namely Magnetorheological (MR) damper. It is shown that the developed evolving TakagiSugeno-Kang (TSK) fuzzy model can identify and grasp the nonlinear dynamics of inverse systems very well, while a small number of inputs and fuzzy rules are required for this purpose.

Azari, B, Fatahi, B & Khabbaz, H 1970, 'Long-term Viscoplastic Behaviour of Embankments Built on Improved Soft Soil Using Vertical Drains', Geo-Congress 2013, Geo-Congress 2013, American Society of Civil Engineers, San Diego, California, pp. 2124-2132.
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In this paper, a nonlinear elastic visco-plastic model is incorporated in the general consolidation equation to investigate the time dependent performance of embankments constructed over deep soft soil deposits stabilised with prefabricated vertical drains (PVDs) and preloading. To model vertical and radial consolidation processes, a finite difference formulation is implemented for fully coupled axisymmetric consolidation. The developed numerical model is validated against Väsby test fill with the available long-term settlement monitoring results for the soft clay deposit improved with PVDs assisted preloading. Practicing engineers can adopt the developed code and guidelines to predict the long term performance of embankments on soft soil consolidated using preloading. © 2013 American Society of Civil Engineers.

Dackermann, U, Li, J & Samali, B 1970, 'Transmissibility function analysis for boundary damage identification of a two-storey framed structure using artificial neural networks', From Materials to Structures: Advancement Through Innovation - Proceedings of the 22nd Australasian Conference on the Mechanics of Structures and Materials, ACMSM 2012, Australasian Conference on the Mechanics of Structures and Materials, CRC press/Balkema, Sydney, Australia, pp. 891-896.
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This paper presents a damage identification technique that uses output-only scalar transmissibility measurements of a structure to identify boundary conditions. A damage index is formulated based on output-only acceleration response measurements from ambient floor vibration. The damage index is analysed by a system of artificial neural networks (ANNs) to predict boundary condition changes of the structure. Using the data compression and noise filtering capabilities of principal component analysis (PCA), the size of the damage index is reduced in order to obtain suitable patterns for ANN training. To test the proposed method, it is applied to different models of a numerical two-storey framed structure with varying boundary conditions. Boundary damage is simulated by changing the condition of individual joint elements of the structure from fixed to pinned. The results of the investigation show that the proposed method is effective in identifying boundary damage in structures based on output-only response measurements. © 2013 Taylor & Francis Group.

DRAGOS, J & WU, C 1970, 'A NEW APPROACH TO DERIVE NORMALIZED PRESSURE IMPULSE CURVES FOR ELASTIC MEMBERS', Journal of Earthquake and Tsunami, World Scientific Pub Co Pte Lt, pp. 1350016-1350016.
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A pressure impulse (PI) diagram is a useful preliminary design tool for structural members against blasts. An extensive amount of investigation has been undertaken to generalize PI curves, using single degree of freedom (SDOF) theory, for elastic structural members. In this study, a new original approach also using SDOF theory, relying on the concept of effective pulse shape, is presented for determining a PI curve for any elastic member. The advantage of this approach is that it can be applied to any given type of blast load. The techniques and equations involved in this approach are outlined. Then, to assess the accuracy of this approach, elastic normalized PI curves generated using the new approach are compared against those obtained using the traditional methods. Finally, this approach is compared against other simplified techniques for determining elastic normalized PI curves.

Fatahi, B, Le, T & Khabbaz, H 1970, 'Influence Of Insitu Stresses On Deformation And Stability Of Embankments On Deep Clays', Proceedings of the International Conference on Ground Improvement and Ground Control, Ground Improvement And Ground Control: Transport Infrastructure Development and Natural Hazards Mitigation, Research Publishing, Wollongong, Australia, pp. 491-496.
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Time dependent behavior of soft soils under embankments is one of the challenging problems in geotechnical engineering, since soft ground has been utilised for development. This paper presents a numerical study of the influence of the initial stress state on the ground lateral deformation and pore water pressure by revisiting a case study of an embankment constructed on Boston Blue Clay. The insitu stress state is usually determined by the coefficient of lateral earth pressure at rest (K0), but there are various correlations to estimate the value of K0. In this paper, a numerical parametric study is conducted to investigate the effect of K0 on the vertical and horizontal displacements, the excess pore water pressures, and the factor of safety of the embankment. The results show that the value of K0 has notable influences on the predictions of horizontal and vertical displacements, but minor effects on the predicted pore water pressures. The choice of the lateral earth pressure coefficient at rest also has impact on the long term stability of the embankment. Thus, it is emphasised that the initial stress state should be concerned regarding the stability of the embankment for analysing the performance of embankments constructed on deep soft soils.

Fatahi, B, Le, T & Khabbaz, H 1970, 'INFLUENCE OF SOIL CREEP ON STABILITY OF EMBANKMENT ON SOFT SOIL', Ground Improvement and Ground Control, International conference on Ground Improvement and Ground Control, Research Publishing, Wollongong, Australia, pp. 485-490.
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As a result of the scarcity of land for construction, number of projects to construct man-made islands or to expand lands over soft grounds keeps increasing. Consolidation and creep are significant in the soft soil and hence, their long term deformation must be taken into account in engineering design and practice. Soil creep has significant impacts on the stability of the structures constructed on the soft ground. In this paper, a case study of an embankment constructed in stages in north Boston over a thick layer of Boston Blue Clay is numerically investigated in order to consider the effects of the soil creep. The behaviour of the ground is simulated using a finite element program associated with and without soil creep. A parametric study on the soil creep ratio is conducted to evaluate its effects on the predictions of the excess pore water pressure and lateral displacement. It is observed that the increase in the value of creep index causes the increases in both of the horizontal displacements and excess pore water pressures of the ground. In addition, the factor of safety against slope instability decreases with the creep ratio. Thus, the effects of soil creep should be earnestly considered in predicting the ground performance under embankments.

Fukumoto, T, Thomas, P, Simon, P & Stuart, BH 1970, 'Estimation of the curing rate of acrylamide used as a consolidant in heritage sandstone conservation', 4th Joint Czech-Hungarian-Polish-Slovak Thermoanalytical Conference Abstracts, 4th Joint Czech-Hungarian-Polish-Slovak Thermoanalytical Conference.

Ghosni, N, Samali, B & Vessalas, K 1970, 'Energy absorption and flexural toughness evaluation of fibre reinforced polymer modified concrete', Proceedings of the 8th International Conference on Fracture Mechanics of Concrete and Concrete Structures, FraMCoS 2013, International Conference on Fracture Mechanics of Concrete and Concrete Structures (FraMCoS-8), International Center for Numerical Methods in Engineering (CIMNE), Toledo, Spain, pp. 1122-1130.
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This paper presents the effect of fibres on the behaviour of fibre reinforced concert (FRC) which nowadays is recognised for its energy absorption capacity as well as other benefits. Incorporating fibres in concrete, results in an ameliorated mix design which can dissipate energy and improve the fracture performance of concrete matrix. There are different types of test methods developed to measure the concrete energy absorption capacity, one of which is the four point bending test. This research work is on the flexural behaviour characterisation of polymer modified synthetic fibre reinforced concrete incorporating polypropylene (PP) fibres and styrene butadiene (SB) latex copolymer. Results of this study show that by adding PP fibres to concrete, toughness and energy absorption characteristics can be enhanced. By increasing the amount of fibre used in the concrete matrix this value can be increased. It has also been concluded that by adding fibres to the concrete matrix, the energy absorption characteristics can consequently be improved.

Gu, X & Li, Y 1970, 'Comprehensive Investigations on Magnetic Field Distribution in a Solenoid', Volume 1: Development and Characterization of Multifunctional Materials; Modeling, Simulation and Control of Adaptive Systems; Integrated System Design and Implementation, ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, American Society of Mechanical Engineers, Snowbird, Utah, USA, pp. 1-7.
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Finding engineering applications for a new class of smart material, magnetorheological elastomer (MRE), has been a major task for researchers in this field. Novel MRE devices, such as vibration absorbers and vibration isolators, have been proposed and fabricated to pioneer its engineering applications. In civil engineering, the author has proposed a novel MRE based isolator to be used in the base isolation system for mitigating the devastating effects of earthquakes on civil structures. For any MRE-based device, electromagnetic coil is evitable involved to provide magnetic field for the MRE materials. Comparing with magnetic circuit design in magnetorheological fluid (MRF) device, i.e. MR damper, MRE devices normally need a larger coil to energize the MRE materials, particularly for a large-scale MRE device. Therefore, investigation of the solenoid on the magnetic field distribution is of great importance for the design and development of MRE based device. In particular, provision of sufficient and uniform magnetic field is essential towards the success in designing MRF/MRE devices. To understand the mechanism of magnetic field generation in a solenoid is the key for device design and optimization. The main objective of this paper is to analytically investigate and experimentally validate the magnetic field distribution in a solenoid. The theoretical investigation starts from the analysis on an ideally thin cylindrical solenoid in order to obtain analytical results. To stimulate the coil which can be used in the design of MRE device, theoretical investigation is to conduct on a thick-wall cylindrical solenoid. Finite element analysis is also used to examine the magnetic field distribution in the solenoid. In order to verify the theoretical findings, experimental testing is conducted to acquire the magnetic field distribution in a sample solenoid. Results from analytical solution, finite element analysis and experimental testing agree very well. ...

Hassani Esgandani, M, Vessalas, K, Baweja, D & Schmidt, Z 1970, 'Assessment of watertight concrete and role of chemical admixtures', Concrete Institute of Australias Biennial National Conference 2013, Concrete Institute of Australia - Biennial Conference, Concrete Institute of Australia¿s, Gold Coast, Australia.

Ho, H, Fatahi, B & Khabbaz, H 1970, 'Exact Solution to Predict Excess Pore Pressures and Settlement of Unsaturated Soil Deposit due to Uniform Loading', GEO Montreal 2013, GeoMontreal, Canadian Geotechnical Society, Hilton Bonaventure Montreal Hotel, pp. 1-6.
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This paper explains a simple yet precise analytical solution for the nonlinear governing equations for one-dimensional (1D) consolidation of an unsaturated soil deposit using eigenfunction expansions and Laplace transform techniques. The mathematical development adopts two-way drainage condition for the unsaturated soil, in which the permeable top and base boundaries allow free dissipation of pore-air and pore-water pressures under uniform loading. Eigenfunctions and eigenvalues are parts of the general solution and can be obtained based on the proposed drainage boundary condition. Furthermore, uniformly distributed initial pore pressures can be used to determine the initial generalised Fourier coefficients. Besides, Laplace transform method is adopted to solve the first-order differential equations. Once the equations with transformed domain are obtained, the final solutions, which are proposed to be functions of time (t) and depth (z), can be achieved by taking an inverse Laplace transform. A worked example is provided to present the consolidation characteristics of unsaturated soils based on the proposed solution. Significance of air permeability to water permeability ratio on the excess pore water and air pressure dissipation rates is investigated and discussed.

Hokmabadi, AS, Fatahi, B & Samali, B 1970, 'Seismic response of superstructure on soft soil considering soil-pile-structure interaction', 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013, International Conference on Soil Mechanics and Geotechnical Engineering, Presses des Ponts, Paris, France, pp. 547-550.
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This paper presents results of shaking table tests and three dimensional numerical simulations to investigate the influence of Soil-Pile-Structure Interaction (SPSI) on the seismic response of mid-rise moment resiting buildings supported by end-bearing pile foundations. Three different cases have been considered, namely: (i) fixed-base structure representing the situation excluding the soil-structure interaction; (ii) structure supported by shallow foundation on soft soil; and (iii) structure supported by end-bearing pile foundation in soft soil. Comparison of the numerical predictions and the experimental data shows a good agreement confirming the reliability of the numerical model. Both experimental and numerical results indicate that soil-structure interaction induces significant increase in the lateral deflections and inter-storey drifts of the structures on both shallow and end-bearing pile foundations in comparison to the fixed base structures. This increase in the lateral deformations and in turn inter-storey drifts can change the performance level of the structure during earthquakes which may be safety threatening.

Indraratna, B, Nimbalkar, S, Anantanasakul, P, Rujikiatkamjorn, C & Neville, T 1970, 'Performance Monitoring of Rail Tracks Stabilized by Geosynthetics and Shock Mats: Case Studies at Bulli and Singleton in Australia', Geo-Congress 2013, Geo-Congress 2013, American Society of Civil Engineers, USA, pp. 19-33.
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Rail tracks are conventionally built on compacted ballast and structural fill embankments overlying the natural subsoil. Ballast plays an important role in providing track stiffness to support heavy traffic loads, and providing rapid drainage. However, ballast deforms and degrades progressively under the heavy cyclic loading of passenger and freight trains, which may lead to a loss of track geometry, and require costly regular maintenance. In particular, track construction requires appropriate stabilization techniques for ballast, the extent of which depends also on the type of subgrade. Comprehensive field trials were carried out on two rail lines in Bulli and recently in Singleton, New South Wales, Australia. In these studies, several track sections were reinforced with different types of geosynthetics placed beneath the ballast embankment. Both fresh and recycled ballast was examined for varying subgrade conditions. Recoverable and irrecoverable deformations of the substructure were routinely monitored. It was found that geogrids and geocomposites can decrease the vertical strains of the ballast layer, resulting in reduced maintenance costs. This paper describes the comprehensive field instrumentation, construction procedures, and field performance evaluation of these full-scale geosynthetic- stabilized ballast embankments in Bulli and Singleton. © 2013 American Society of Civil Engineers.

Indraratna, B, Nimbalkar, S, Rujikiatkamjorn, C, Neville, T & Christie, D 1970, 'Performance assessment of synthetic shock mats and grids in the improvement of ballasted tracks', 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013, pp. 1283-1286.
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In Australia, railways offer the most prominent transportation mode in terms of traffic tonnage serving the needs of bulk freight and passenger movement. Ballast is an essential constituent of conventional rail infrastructure governing track stability and performance. However, in recent times, higher traffic induced stresses due to dramatically increased train speeds and heavier axle loads have caused excessive plastic deformations and degradation of ballast. This seriously hampers safety and efficiency of express tracks, for instance, enforcing speed restrictions and effecting more frequent track maintenance. Installing layers of synthetic materials such geogrids and rubber pads (shock mats) in rail tracks can significantly reduce ballast degradation. Field trials were conducted on rail track sections in the towns of Bulli (near Wollongong City) and Singleton (near Newcastle) to measure track deformations associated with cyclic stresses and impact loads. This paper describes the results of large-scale laboratory testing as well as the observations from full-scale instrumented field trials characterising the behaviour of rail ballast improved by shock mats and synthetic grids.

Indraratnaa, B, Tennakoon, N, Nimbalkar, S & Rujikiatkamjorn, C 1970, 'Effects Of Fouling On The Stress—Strain—Degradation Behaviour Of Rail Ballast', Proceedings of the 18th Southeast Asian Geotechnical Conference (18SEAGC) & Inaugural AGSSEA Conference (1AGSSEA), 18th Southeast Asian Geotechnical Conference (18SEAGC) & Inaugural AGSSEA Conference (1AGSSEA), Research Publishing Services.
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Jiang, X, Li, Y & Li, J 1970, 'A piezoelectric wafer-stack vibration energy harvester for wireless sensor networks', SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2013, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, SPIE, San Diego, USA, pp. 1-9.
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Over the past few decades, wireless sensor networks have been widely used in civil structure health monitoring application. Currently, most wireless sensor networks are battery-powered and it is costly and unsustainable for maintenance because of the requirement for frequent battery replacements. As an attempt to address such issue, this paper presents a novel piezoelectric vibrational energy harvester to convert the structural vibration into usable electrical energy for powering wireless sensor networks. Unlike the normal cantilever beam structure, the piezoelectric harvester presented in this paper is based on the wafer-stack configuration which is suitable for applications where large force vibration occurs, and therefore can be embedded in civil structures to convert the force induced by vibration of large structures directly into electrical energy. The longitudinal mode of the piezoelectric wafer-stack was developed firstly to illustrate the force-to-voltage relationship of piezoelectric materials and to find the inter-medium force that will be used to convert vibration energy into electrical energy. Then, two electromechanical models (without and with a rectified circuit), considering both the mechanical and electrical aspects of the harvester, were developed to characterize the harvested electrical power under the external load. Exact closed-form expressions of the electromechanical models have been derived to analyze the maximum harvested power and the optimal resistance. Finally, a shake table experimental testing was conducted to prove the feasibility of the presented piezoelectric-wafer-stack harvester under standard sinusoidal loadings. Test results show that the harvester can generate a maximum 45mW (AC) or 16mW (DC) electrical power for sinusoidal loading with 40mm amplitude and 2Hz frequency, and the harvested electrical power is proportional to the levels of exciting vibrational loading. © 2013 SPIE.

Jiang, XZ, Li, YC & Li, JC 1970, 'A novel piezoelectric wafer-stack vibration energy harvester', From Materials to Structures: Advancement Through Innovation - Proceedings of the 22nd Australasian Conference on the Mechanics of Structures and Materials, ACMSM 2012, Australasian Conference on the Mechanics of Structures and Materials, CRC press/Balkema, Sydney, Australia, pp. 399-404.
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Piezoelectric vibration-based energy harvesters are attractive as inexhaustible replacements for batteries in low-power requirement wireless electronic devices and thus have received increasing research interest in the last few years. This paper presents a novel piezoelectric harvester based on the wafer-stack configuration to convert the external vibration into usable electrical energy for this purpose. Both analytical and experimental investigations are undertaken at University of Technology Sydney. Firstly, an electromechanical model with a rectified circuit, considering both the mechanical and electrical factors of the harvester, is built to characterise the harvested electrical power across the external loadings. Exact closed-form expressions of the electromechanical model have been given to analyse conditions for maximum harvested power. Finally, a shake table experimental testing was conducted to evaluate the feasibility of the presented PZT wafer stack harvester under standard sinusoidal loadings. Test results show that the harvester can generate a maximum 16mW electrical power for sinusoidal loading with 40mm amplitude and 2Hz frequency. © 2013 Taylor & Francis Group.

Jozi, BJ, Dackermann, U, Braun, RB, Li, JL & Samali, BS 1970, 'Separation of bi-directional stress waves for the non-destructive condition assessment of in-service timber utility', 6th International Conference on Structural Health Monitoring of Intelligent Infrastructure (SHMII-6), International Conference on Structural Health Monitoring of Intelligent Infrastructure, Hong Kong.
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Timber utility poles represent a significant part of Australia’s infrastructure for power distribution and communicationnetworks. Due to the advanced age of Australia’s timber pole infrastructure, significant efforts are undertaken by stateauthorities on maintenance and asset management to prevent utility lines from failure. However, the lack of reliabletools for assessing the condition of in-service poles seriously jeopardizes the maintenance and asset management. Forexample, each year approximately 300,000 poles are replaced in the Eastern States of Australia with up to 80% of themstill being in a very good serviceable condition, resulting in significant waste of natural resources and money.

Khabbaz, H, Shrestha, B & Fatahi, B 1970, 'Parametric Study On Behavior Of Reinforced Soil Walls With Combined Horizontal And Vertical Geosynthetics', PROCEEDINGS OF THE 2013 AGS SYMPOSIUM - Retaining Structures: Recent Advances and Past Experiences -, AGS Symposium – Retaining Structures: Recent Advances and Past Experiences, The Australian Geomechanics Society, Sydney, Australia, pp. 173-181.
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The reinforced soil system employing geogrids, as a cost effective reinforcement technique, has come to play an important role in a variety of civil and geotechnical engineering applications. In regular reinforced soil wal1s, the reinforcements are usually laid horizontally in the soil. In this study, the behaviour of reinforced soil retaining walls with combined horizontal and vertical reinforcements are investigated experimentally as well as numerically. The results, indicating the effects of vertical reinforcement inclusion, are compared to conventional reinforcing types under static and dynamic loads. The performance of retaining walls employing vertical reinforcement in conjunction with horizontal reinforcement is convincing from the results of the shake table tests conducted by the authors. In this paper, PLAXIS, well-known geotechnical software, is used for conducting a series of pararoetric studies on behaviour of reinforced soil walls under construction and subject to earthquake loading, incorporating the vertical reinforcement. The vertical reinforcement layout and its strength are among the major variables of the investigation. The geometry of the model, soil properties and reinforcement characteristics have been kept identical in all different cases selected for parametric studies. The performance of the wall is presented for the facing deformation and crest surface settlement, lateral earth pressure, tensile force in the reinforcement layers and acceleration amplification. The vertical ctefOlIDation, horizontal deflection, reinforcement force and earth pressure develop drastically under earthquake loading compared to the end of construction. The results show that these variables are considerably reduced when incorporating the vertical reinforcement in the system. In addition, the findings suggest better performance and higher structural safety for reinforced soil walls, when employing this proposed orthogonally horizontal-vertical geosynthetics.

Le, TM, Van Le, P, Khabbaz, H & Fatahi, B 1970, 'Stability and Deformation of Sheet Pile Walls for Protecting Riverside Structures in the Mekong River Delta', Geo-Congress 2013, Geo-Congress 2013, American Society of Civil Engineers, San Diego, California, pp. 1349-1358.
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Regions of the Mekong River Delta consist of soft soil, which causes significant issues on the stability and deformation of the surrounding structures, especially the riverside structures. Sheet pile walls are considered as one of the effective methods used to support the riverside structures against soil sliding and flooding. This paper presents a precise study on the stability and deformation of sheet pile walls constructed along the riverside areas in the Mekong River Delta. An approach founded on the limit equilibrium method is proposed to solve the equilibrium equations of lateral forces and moments. The proposed approach allows the designed depth of embedment to be determined by the factor of safety. Additionally, it is a simple method to analyze the performance of sheet walls in multi-layered ground conditions. A program code is written to implement the proposed method. In this paper, in order to evaluate the stability and deformation of the walls, the prediction results obtained by the developed method are compared to the results by finite element analysis. Furthermore, the results show that the predicted maximum lateral movement of the wall is in reasonable agreement with the field measurement. © 2013 American Society of Civil Engineers.

Li, J, Li, Y, Li, W & Samali, B 1970, 'Development of adaptive seismic isolators for ultimate seismic protection of civil structures', SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2013, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, SPIE, San Diego, USA, pp. 1-12.
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Base isolation is the most popular seismic protection technique for civil engineering structures. However, research has revealed that the traditional base isolation system due to its passive nature is vulnerable to two kinds of earthquakes, i.e. the near-fault and far-fault earthquakes. A great deal of effort has been dedicated to improve the performance of the traditional base isolation system for these two types of earthquakes. This paper presents a recent research breakthrough on the development of a novel adaptive seismic isolation system as the quest for ultimate protection for civil structures, utilizing the field-dependent property of the magnetorheological elastomer (MRE). A novel adaptive seismic isolator was developed as the key element to form smart seismic isolation system. The novel isolator contains unique laminated structure of steel and MR elastomer layers, which enable its large-scale civil engineering applications, and a solenoid to provide sufficient and uniform magnetic field for energizing the field-dependent property of MR elastomers. With the controllable shear modulus/damping of the MR elastomer, the developed adaptive seismic isolator possesses a controllable lateral stiffness while maintaining adequate vertical loading capacity. In this paper, a comprehensive review on the development of the adaptive seismic isolator is present including designs, analysis and testing of two prototypical adaptive seismic isolators utilizing two different MRE materials. Experimental results show that the first prototypical MRE seismic isolator can provide stiffness increase up to 37.49%, while the second prototypical MRE seismic isolator provides amazing increase of lateral stiffness up to 1630%. Such range of increase of the controllable stiffness of the seismic isolator makes it highly practical for developing new adaptive base isolation system utilizing either semi-active or smart passive controls. © 2013 SPIE.

Li, W, Xiao, J, Corr, DJ & Shah, SP 1970, 'Numerical modeling on the stress-strain response and fracture of modeled recycled aggregate concrete', 13th International Conference on Fracture 2013, ICF 2013, International Conference on Fracture, Beijing, China, pp. 749-759.
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According to the nanoindentation tests, the constitutive relationship of the Interfacial Transition Zones (ITZs) in Recycled Aggregate Concrete (RAC) is proposed with a plastic-damage constitutive model. Based on the meso/micro-scale constitutive relations of mortar matrix, numerical studies were undertaken on Modeled Recycled Aggregate Concrete (MRAC) under uniaxial loadings to predict mechanical behavior, particularly the stress-strain response. The tensile stress tends to concentrate in the ITZs region, which leads to the development of microcracks. After the calibration and validation with experimental results, the effects of the mechanical properties of ITZs and new mortar matrix on the stress-strain response and fracture of MRAC were analyzed. The FEM modeling is capable of simulating the complete stress-strain relationship of MRAC, as well as the overall fracture pattern. It reveals that the mechanical properties of new mortar matrix and the corresponding new ITZ play a significant role in the overall stress-strain response and fracture process of MRAC.

Li, Y, Li, J, Li, W & IEEE 1970, 'Design and Experimental Testing of an Adaptive Magneto-Rheological Elastomer Base Isolator', 2013 IEEE/ASME INTERNATIONAL CONFERENCE ON ADVANCED INTELLIGENT MECHATRONICS (AIM): MECHATRONICS FOR HUMAN WELLBEING, IEEE/ASME International Conference on Advanced Intelligent Mechatronics, IEEE, Wollongong, Australia, pp. 381-386.
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Magnetorheological elastomer (MRE) is known for its field-sensitive shear modulus and damping property when it is exposed to a magnetic field. It has a great potential for the development of vibration reduction devices. Many research, mostly in mechanical engineering, have been focused on different kinds of vibration absorbers and vibration isolators, however few research addresses its potential in base isolation system in civil engineering application. The objective of this paper is to pilot the design and experimental testing of a novel device, an adaptive MRE base isolator, for the development of smart base isolation system. A large-scale design of the novel device with unique laminated structure of steel and MR elastomer layers is adopted. Detailed procedures on designing such adaptive base isolator are introduced. An innovative design on the magnetic circuit, with aim to provide strong and uniform magnetic field to the multi-layer MRES, is proposed to incorporate into the device design. Experimental investigation is conducted to examine its behavior under various cycling loadings when it is applied with different current inputs. Experimental results indicated that the force increase and the stiffness increase of the novel device are about 45% and 37%, respectively. To conclude, the MR elastomer base isolator will be a promising candidate to facilitate the development of adaptive base isolation system for civil structures. © 2013 IEEE.

Li, Y, Wang, J & Kong, X 1970, 'Zero velocity update with stepwise smoothing for inertial pedestrian navigation', International Global Navigation Satellite Systems Society 2013 Symposium Proceedings, International Global Navigation Satellite Systems Society, Menay Pty Ltd, Australia, Surfers Paradise, Australia, pp. 1-10.
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Zero velocity update (ZUPT) is an effective way to correct low cost inertial measurement unit (IMU) errors when it is foot-mounted for pedestrian navigation. The stance phase in steps provides zero velocity measurement for inertial sensor error correction. As the errors of IMU estimated position and velocity grow rapidly with time between each correction, ZUPT applied at each step leads to sharp corrections and discontinuities in the estimated trajectory. For motion analysis and visualization, these large corrections are undesirable. Consequently, the implementation of smoothing for ZUPT-aided INS is considered to eliminate the sharp corrections. In this paper, we propose a closed loop Rauch-Tung-Striebel (RTS) smoother using a 24 error states extended Kalman filter (EKF) implement on our previous pedestrian navigation systems. Unlike common RTS smoother which operates as off-line processing mode, a near-real-time stepwise smoother is implemented to eliminate the sharp corrections over the steps. The impact of the near real-time smoothing filter for different step manners (walk, run and climb stairs) combined with the Constant Velocity Update (CUPT) concept we proposed previously is illustrated and analysed. Experimental results show that the proposed method can dramatically improve pedestrian navigation smoothness.

Metia, S, Oduro, SD, Ha, QP & Duc, H 1970, 'Environmental Time Series Analysis and Estimation with Extended Kalman Filtering', 2013 FIRST INTERNATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE, MODELLING AND SIMULATION (AIMS 2013), International Conference on Artificial Intelligence, Modelling and Simulation, IEEE, Kota Kinabalu, Sabah, Malaysia, pp. 235-240.
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© 2013 IEEE. This paper addresses the problem of air pollutant profile estimation by using measurements collected from different weather stations. An algorithm is developed, based on an Extended Kalman Filter to handle missing temporal data and using the statistical Kriging method to interpolate spatial data. Combination of extended Kalman filtering with Matérn covariance function has proven to be useful in exploiting meteorological information to build reliable air quality models. We have applied the developed algorithm to estimate air pollutant profiles in the Sydney basin, which is subject to a variety of pollutant sources, including fossil-fueled electric power generation plants, high motor vehicle usage, aviation and shipping traffic. The results have shown that the proposed approach can improve accuracy of the estimation profiles.

Moshiri, F, Gerber, C, Valipour, HR, Shrestha, R & Crews, KI 1970, 'The predictive model for strength of inclined screws as shear connection in timber-concrete composite floor', From Materials to Structures: Advancement Through Innovation - Proceedings of the 22nd Australasian Conference on the Mechanics of Structures and Materials, ACMSM 2012, Australasian Conference on the Mechanics of Structures and Materials, CRC PRESS / BALKEMA, SYDNEY, AUSTRALIA, pp. 1059-1064.
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Interest in timber-concrete composite (TCC) floors has increased over the last 30 years. TCC technology relies on timber and concrete members acting compositely together. Both timber and concrete exhibit a quite brittle behaviour in bending/tension and compression respectively whilst the shear connection is identified as the only contributor of ductile behaviour. Therefore, the strength, stiffness and arrangement of the shear connection play a crucial role in the structural design of TCC. There are only few investigations on analytical closed-form equation to predict the stiffness and strength of TCC joints as input values to design a partially composite floor. For example, Johansen's yield theory was adopted as European yield model in Eurocode 5. However, the equations are limited to vertically inserted dowels or screws and Eurocode 5 recommends that the strength and stiffness of unconventional joints should be determined by push-out tests. Previous investigations reported that the inclined shear connector significantly increase the initial stiffness and ultimate strength of the TCC joints and consequently composite floor. This paper presents a model for the strength ofTCC joint using crossed (±45°) proprietary screws (SFS Intec). The Johansen yield theory is extended to derive the strenght model of TCC joint with crossed (±45°) screws which are loaded in tension and compression. The model is an upper bound plastic collapse model that assumes the behaviour of timber and screw perfectly plastic with undamaged concrete. The failure modes considers of yield of screw, in tension or shear, and some combined modes assuming screw withdrawal, lateral crushing of the timber and the development of plastic hinges in the screw. The experimental aspect of the research consists of push-out tests and aims to verify the strength model of TCC joints with inclined screws. The failure modes are also investigated. The model seems to be reasonably accurate in predicting bo...

Moshiri, F, Shrestha, R & Crews, K 1970, 'Investigation on TCC systems using self-compacting concrete', Proceedings of the 13th East Asia-Pacific Conference on Structural Engineering and Construction, EASEC 2013, East Asia-Pacific Conference on Structural Engineering and Construction, Sapporo, Japan.
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Interest in timber-concrete composite (TCC) floors has increased over the last 20-30 years. Since the 1990's, TCC solution is seen as a viable and effective alternative to conventional reinforced concrete and/or traditional timber floors in multi-storey buildings. TCC technology relies on timber and concrete members acting compositely together. Thus, the strength, stiffness, location and number of connectors play a crucial role for the composite action and determine the structural and serviceability performance of TCC solutions. To date, conventional concrete (CC) has been used in most investigations on TCCs. Also, there are only few researches about the effect of concrete properties on the structural behaviour of TCCs. Self-compacting concrete (SCC) is highly workable and can be compacted without use of conventional vibration methods. As such, there is a potential for application of SCC in difficult to access areas or areas where complex formwork make it difficult to use conventional vibration methods. University of Technology Sydney has investigated TCC solutions since 2007. The investigation presented in this paper focuses on utilising mechanical fasteners for their ductility and stiffness to compositely attach a SCC slab to a timber beam and to investigate the effect of use of SCC on the behaviour of such connections. The experimental aspect of the research consists of push-out tests and aims to characterise slip modulus and load capacity. The responses of the specimens are also compared to that of TCC systems with conventional concrete. The failure modes of the connections are also studied.

Nabavi, F, Nejadi, S & Samali, B 1970, 'Experimental Investigation on Mix Design and Mechanical Properties of Polymer (Latex) Modified Concrete', PROGRESS IN POLYMERS IN CONCRETE, International Congress on Polymers in Concrete, TransTech, Shanghai, China, pp. 112-117.
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This paper presents the experimental investigation to enhance the mechanical properties of Polymer Modified Concrete (PMC) incorporating Styrene Butadiene Rubber (SBR) and describes the potential of using PMC as a structural material. PMC has been used for many years as an over layer in the bridges deck or for the repairing the defected concrete structures subjected to marine environment. But, because of low compressive strength due to foaming phenomenon, PMC has not been considered as a structural concrete. In this study, a range of investigations including sensitivity of PMC to water cement ratio, the effect of SBR proportion on compressive strength and modulus of rupture, selection of the proper antifoaming agent, the effect of various curing methods on compressive strength, proper mix design of PMC to achieve medium to highcompressive strength are carried out. Also, the instructions for casting PMC are composed which can be stated as a standard for mixing and curing procedure of PMC. Results show that increasing the proportion of latex in PMC causes the strength reduction. But, using appropriate antifoaming agent (defoamer) and proper curing method, the mechanical properties can be recovered remarkably. © (2013) Trans Tech Publications, Switzerland.

Nguyen, L, Fatahi, B & Khabbaz, H 1970, 'Predicting behaviour of cemented clay considering strength reduction due to high confining pressure', GeoMontreal 2013, GeoMontreal, Canadian Geotechnical Society, Montreal, Canada, pp. 1-6.
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A predictive constitutive model referred to as Cemented Cam Clay (CCC) model developed by the authors is presented in this paper to precisely predict the behaviour of cemented clay capturing the effect of cementation degradation during loading. When the confining pressure increases, the effect of cementation gradually diminishes due to the breakdown of cementation bonds as observed in laboratory experiments. The proposed model includes a non-associated plastic potential function and elasto-plastic stress-strain relationship inspired by the framework of the critical state concept. The main feature of the proposed model is the formulation of the failure envelope which describes the beneficial effect of cementation at low pressure range. As the confining pressure continues to increase, it gradually merges with the critical state line indicating a degradation of cement bonding. The proposed model is validated through comparison of the model predictions with the results of an array of triaxial tests conducted on Ariake cemented clay.

Nguyen, V, Fatahi, B & Khabbaz, H 1970, 'Three dimensional numerical simulation to predict performance of laterally loaded piles on clay-sand layered slope', GeoMontreal2013, GeoMontreal, GeoMontreal2013, Montreal, Quebec, pp. 1-6.
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Predicting the deformation of the laterally loaded piles constructed on a slope is one of the challenging issues in foundation engineering. Numerical modelling is an efficient method to investigate the effects of the distance from the pile centreline to the slope crest on the performance of laterally loaded piles considering the shear plastic deformations of the ground. In this paper, finite element software, ABAQUS, has been employed to simulate the performance of some piles subjected to lateral loads in the sloping ground including sand and clay layers. Appropriate subroutines have been adopted to simulate the soil-pile interface, capable of incorporating the gapping and sliding in the soil-pile interfaces for both sand and clay layers. The numerical results are used to predict the lateral load-deformation of piles for various cases and validated through comparison with an array of full scale field measurements.

Parsa-Pajouh, A, Fatahi, H & Khabbaz, B 1970, 'Numerical analysis to quantify the influence of smear zone characteristics on preloading design in soft clay', 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013, International Conference on Soil Mechanics and Geotechnical Engineering, Presses des Ponts, Paris, France, pp. 2573-2576.
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In this paper, the effects of uncertainties of smear zone characteristics induced by installation of prefabricated vertical drains on the preloading design are numerically investigated. FLAC 2D finite difference software with additional developed subroutines has been employed to conduct the numerical simulations. The finite difference analyses have been verified using a case study. Furthermore, a comprehensive parametric study is conducted to investigate the influence of smear zone permeability and extent on the model predictions. Results of this study indicate that the assumptive properties for smear zone characteristics may result in inaccurate predictions of ground deformations and pore water pressures. This may lead to early removal of the surcharge in the construction process causing excessive post construction settlement. It is recommended to practising engineers to use results of trial preloading to back calculate the required smear zone characteristics in the early stages of embankment construction to optimize the design.

Shrestha, R, Baweja, D, Neupane, K, Chalmers, D & Sleep, P 1970, 'Mechanical Properties of Geopolymer Concrete: Applicability of Relationships Defined by AS 3600', Concrete 2013, Concrete Institute of Australia - Biennial Conference, Concrete Institute of Australia, Gold Coast, Queensland.
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Geopolymers are new inorganic polymer binders; synthesised from aluminosilicate powders such as fly ash and blast furnace slag with alkali activators and producing good binding properties similar to ordinary Portland cement (OPC). This new generation binding material has a potential application in structural and non-structural concretes, fire resistant composites and ceramics. Previous research around the world has suggested that geopolymer binders possess superior engineering, mechanical and durability properties over conventional Portland cement. The process of setting and hardening of geopolymer concrete is based on different chemistry called Polymerization instead of Hydration in OPC. The silicon and aluminium oxides in the source materials are activated by a combination of sodium hydroxide and sodium silicate in presence of water to form a sodium aluminosilicate paste called Geopolymer which has binding properties similar to CSH in OPC. In this study, some engineering and mechanical properties of different grades of Geopolymer concrete were tested and evaluated according to relevant Australian Standards and compared against the same grade of OPC concrete. Australian Standard AS 3600 describesinterrelationships between different mechanical properties of concrete such as compressive strength and uniaxial tensile strength and compressive strength and flexural tensile strength. From this study, it is found that uniaxial tensile and flexural tensile strengths attained by the geopolymer concretes investigated were higher than those prescribed by AS 3600 for the given grade of concrete. Modulus of elasticity, however, was found to be similar to calculated values provided by AS 3600 for similar grades of concrete. This suggests that geopolymer concretes of the type investigated may be used in selected structures using design procedures currently available. Further verification work on this is currently under way.

Sriravindrarajah, R, Mohammad, KJ & Singh, A 1970, 'Permeability and drying of pervious concrete pavers', ISEC 2013 - 7th International Structural Engineering and Construction Conference: New Developments in Structural Engineering and Construction, New Developments in Structural Engineering and Construction, Hawaii, USA, pp. 1703-1707.
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Pervious concrete, a tailored concrete with connected large-sized voids, allows the water to flow through easily. In-situ pervious concrete pavements is produced with no or minimum compaction with fairly dry but workable concrete mix. This construction method contributes to variable permeability and strength performance within the pervious concrete pavements. In order to improve the reliability of pervious concrete pavements the use of precast pervious pavers produced with strict quality control is a possible solution. This paper reports the results of an investigation into the performance of 300 mm by 300 mm by 75 mm matured laboratorymade pervious concrete pavers, in relation to overall water permeability, variability of water permeability within each paver and rate of drying of saturated pavers at 20°C, 30°C and 40°C. The void content of the twelve precast pavers used in this study is varied between 12% and 22%. The results showed: (a) the existence of non-uniformity of water permeability within a pervious concrete paver independent of its porosity; (b) an increase in the thickness of the pervious concrete paver decreased the water infiltration rate; (c) with the decrease in the void content the overall permeability of the pervious concrete pavers is decreased; (d) the drying rate of pervious slabs is increased with the increase in temperature; (e) the influence of void content on dry rate is reduced with the increase in the drying temperature.

Tabatabaiefar, HR, Fatahi, B & Samali, B 1970, 'Inelastic lateral seismic response of building frames under influence of bedrock depth variations incorporating soil-structure interaction', From Materials to Structures: Advancement Through Innovation - Proceedings of the 22nd Australasian Conference on the Mechanics of Structures and Materials, ACMSM 2012, Australasian Conference on the Mechanics of Structures and Materials, CRC press/Balkema, Sydney, Australia, pp. 587-592.
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In this study, a fifteen storey moment resisting building frame is selected in conjunction with a soft clayey soil, representing soil class Ee, according to Australian Standards. Different bedrock depths including 10 m, 20 m, and 30m are employed in the numerical modelling using finite difference software FLAC 2D. The above mentioned frame has been analysed under two different boundary conditions: (i) fixed-base (no soilstructure interaction), and (ii) flexible-base (considering soil-structure interaction). Inelastic dynamic analyses under influence of different earthquake records for three mentioned bedrock depths are conducted, and the results in terms of inelastic lateral deflections and inter-storey drifts for the above mentioned boundary conditions are compared and discussed. The results indicate that the bedrock depth variations play a significant role in inelastic lateral seismic response of the building frame under the influence of soil-structure interaction. As the bedrock depth increases, lateral deflections and inter-storey drifts of the structures increase. The mentioned effects can change the performance level of the structures from life safe to near collapse or total collapse. © 2013 Taylor & Francis Group.

Tao, M, Wu, C & Li, X 1970, 'Numerical simulation of multiple fracture zones in underground dynamic loading processes', Rock Dynamics and Applications - State of the Art: Proceedings of the 1st International Conference on Rock Dynamics and Applications, RocDyn-1 2013, International Conference on Rock Dynamics and Applications (RocDyn), CRC Press, Lausanne, Switzerland, pp. 451-456.
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The excavation fracture responses around cavities in rock mass with initial stress were examined using three dimensional numerical modelling. In addition to the primary fractured zone in near field, numerical modelling generated the second fractured zone in far field, and an elastic non-fractured zone between the two fractured zones, i.e., the fractured zones and the non-fractured zone occur alternately around deep cavity. This finding proved that the zonal disintegration phenomenon can occur in underground excavation process. © 2013 Taylor & Francis Group.

Thomas, D, Ding, GK & Crews, KI 1970, 'Medium-rise structural timber apartment: Luxury or long-term carbon storage solution?', Proceedings of the Sustainable Buildings - Construction Products & Technologies, Sustainable Buildings - Construction Products & Tecnologies, Graz University of Technology, Graz, Austria, pp. 647-654.
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The Australian construction sector contributes almost a quarter of the nations carbon emissions and the main strategy to address this has been to reduce the operating energy of existing buildings and by regulating energy consumption of new buildings. However there has been less focus on minimizing the embodied energy of new construction projects. Engineered timber products have been used in a number of large building projects to replace heavier materials as a structural alternative whilst providing benefits such as aesthetics and the capacity to store carbon. Cross-laminated timber (CLT) has found a market in apartment buildings in Europe with a growing number of projects using the product for both structural floors and walls up to 9 storeys high. Australia's first major CLT building stands 10 storeys high and is currently being marketed as a sustainable city apartment alternative to reinforced to reinforced concrete. This paper looks at the perception of consumers towards this new construction innovation in an attempt to understand whether Australian residents will accept sustainable timber use in apartment living.

Tran, T & Ha, QP 1970, 'Plug-and-play predictive control of modular nonlinear systems with coupling delays', 2013 IEEE International Conference on Automation Science and Engineering (CASE), 2013 IEEE International Conference on Automation Science and Engineering (CASE 2013), IEEE, Madison, Wisconsin, USA, pp. 699-704.
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This paper presents a decentralized model predictive control strategy for nonlinear network systems having multiple coupling delay elements. Linear interconnections, whose topologies are defined by an unweighted Laplacian matrix, and persistent input disturbances are considered in this development. On the ground of the incrementally accumulative quadratic constraint presented previously, the time-domain robust stabilizability conditions for nonlinear interconnected systems are developed in this work. To deal with multiple coupling delays, the accumulative dissipativity criteria for subsystems are derived for use with the accumulatively asymptotic dissipativity constraint (aADC) in the stabilizability conditions. aADC is an asymptotic constraint on the accumulation of supply rates over the window of delay time interval. A compound output in the supply rate is deployed such that the dissipativity criterion can be rendered in linear matrix inequalities. A convex stability constraint for the local optimization of the model predictive control in a fully decentralized architecture is then derived for implementations. Numerical simulation for a petrochemical process is provided to illustrate the theoretical developments. © 2013 IEEE.

Tran, T & Ha, QP 1970, 'Self-recovery control for dependable systems', 2013 IEEE International Conference on Automation Science and Engineering (CASE), 2013 IEEE International Conference on Automation Science and Engineering (CASE 2013), IEEE, Madison, Wisconsin, USA, pp. 45-50.
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The task of managing duty-standby controllers in building a dependable computerised-control system with wireless sensor networks is challenging owing to the scarcity of both information and processing resources. A novel synchronization method for redundant controllers applying techniques from dissipative systems theory is presented in this paper. As an alternative to the control summation in classical reliable control systems, only one scalar variable, which is the calculated supply rate, is exchanged among the member controllers. Thanks to this one-variable and autonomous-based approach, the reliability requirement will be met under the temporal constraint of real-time controllers whilst overcoming the latency issue and low data-package rates in wireless networks. A dissipation-based quadratic constraint with respect to the control and output increments is developed for these redundant controllers. When a failure is detected, the constraint of the standby controller will be activated from the lower bound of the supply rate being transferred from the duty controller. During the transition time, this constraint is imposed on the output increment such that the transition between the duty and standby controllers will be smooth for the output vector. © 2013 IEEE.

Xuezheng Jiang, Yancheng Li & Jianchun Li 1970, 'Design of a novel linear permanent magnet vibration energy harvester', 2013 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, 2013 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM), IEEE, Wollongong, Australia, pp. 1090-1095.
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This paper presents a novel linear tubular permanent magnet (PM) energy harvester to scavenge energy from ambient vibrations. The proposed linear PM energy harvester consists of a mover attached with PMs and a slotted stator with build-in two-phase electromagnetic coils to induce the electromagnetic induction for converting vibrations into useful electrical energy. The magnetic circuit model of the PM harvester is built to analyze the parameters about scavenging energy and used to optimize the non-dimensional geometry factors and the structural parameters in order to maximize harvested energy under given vibration and space conditions. To confirm the design, dynamic FE simulations were conducted and compared with the analytical results. Simulation results indicate that the proposed PM harvester is able to scavenge about 100 W DC power when the RMS of vibration velocity equals to 0.4 m/s. Also, the harvested power increases as the vibration velocity increasing. © 2013 IEEE.

Zabihi, Z, Shrethta, R, Samali, B & Crews, K 1970, 'Ultimate performance of timber connection with normal screws', From Materials to Structures: Advancement Through Innovation - Proceedings of the 22nd Australasian Conference on the Mechanics of Structures and Materials, ACMSM 2012, Australasian Conference on the Mechanics of Structures and Materials, CRC PRESS / BALKEMA, Sydney, Australia, pp. 1083-1088.
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This paper presents the results of experimental push-out tests on two different types of timber composite connections using only normal screws as the shear connecter. The push out tests were conducted based on Eurocode 5 recommendations and the load-slip responses obtained from lab tests are used to determine the stiffness of the connections at serviceability, ultimate and near collapse levels, and the performance of the connections are assessed at ultimate load. Moreover, an analytical model is derived for each type of connection based on the experimental results and using a non linear regression, which can be implemented into non-linear FE analysis of timber beams with normal screws. © 2013 Taylor & Francis Group.