Case definition and holistic model modifications required for building elements

This project is an extension of a previous CRC project (220-059-B) which developed a program for life prediction of gutters in Queensland schools. A number of sources of information on service life of metallic building components were formed into databases linked to a Case-Based Reasoning Engine which extracted relevant cases from each source.

Report : holistic model modifications for selected building elements

This project is an extension of a previous CRC project (220-059-B) which developed a program for life prediction of gutters in Queensland schools. A number of sources of information on service life of metallic building components were formed into databases linked to a Case-Based Reasoning Engine which extracted relevant cases from each source.

Report : colorbond degradation model

This report documents work carried out in order to develop and prove a model for predicting the lifetime of painted metal components, with a particular emphasis on Colorbond® due to its prominent use throughout Australia. This work continues on from previous developments reported in 2002-059-B No. 12 [1]. Extensions of work included the following research: (1) Experimental proving of the leaching of chromate inhibitors from Colorbond® materials. (2) Updated models for the accumulation of salts and the time of wetness for gutters, based upon field observations. (3) Electrochemical Impedance Spectroscopy investigations aimed at correlating the corrosion rates of weathered Colorbond® with those predicted by modeling.

Damage propagation in reinforced concrete frames under external blast loading

Iconic and significant buildings are the common target of bombings by terrorists causing large numbers of casualties and extensive property damage. Recent incidents were external bomb attacks on multi-storey buildings with reinforced concrete frames. Under a blast load circumstance, crucial damage initiates at low level storeys in a building and may then lead to a progressive collapse of whole or part of the structure. It is therefore important to identify the critical initial influence regions along the height, width and depth of the building exposed to blast effects and the structure response in order to assess the vulnerability of the structure to disproportionate and progressive collapse. This paper discusses the blast response and the propagation of its effects on a two dimensional reinforced concrete (RC) frame, designed to withstand normal gravity loads. The explicit finite element code, LS DYNA is used for the analysis. A complete RC portal frame seven storeys by six bays is modelled with reinforcement details and appropriate materials to simulate strain rate effects. Explosion loads derived from standard manuals are applied as idealized triangular pressures on the column faces of the numerical models. The analysis reports the influence of blast propagation as displacements and material yielding of the structural elements in the RC frame. The effected regions are identified and classified according to the load cases. This information can be used to determine the vulnerability of multi-storey RC buildings to various external explosion scenarios and designing buildings to resist blast loads.

The supervision of doctoral dissertations using a collaborative cohort model

The Collaborative Cohort Model (CCM) for research supervision was developed and piloted as an alternative to the Apprentice Master Model (AMM), which is currently used with most doctoral dissertations. The CCM was developed in response to concerns about completion rates and the quality of research supervision. The feedback from the initial cohort of doctoral students who have experienced the model is presented.

A feasibility study for model based estimating for concrete bridges.

Designing and estimating civil concrete structures is a complex process which to many practitioners is tied to manual or semi-manual processes of 2D design and cannot be further improved by automated, interacting design-estimating processes. This paper presents a feasibility study for the development an automated estimator for concrete bridge design. The study offers a value proposition: an efficient automated model-based estimator can add value to the whole bridge design-estimating process, i.e., reducing estimation errors, shortening the duration of success estimates, and increasing the benefit of doing cost estimation when compared with the current practice. This is then followed by a description of what is in an efficient automated model-based estimator and how it should be used. Finally the process of model-based estimating is compared with the current practice to highlight the values embedded in the automated processes.

A user driven data mining process model and learning system

This paper deals with the problem of using the data mining models in a real-world situation where the user can not provide all the inputs with which the predictive model is built. A learning system framework, Query Based Learning System (QBLS), is developed for improving the performance of the predictive models in practice where not all inputs are available for querying to the system. The automatic feature selection algorithm called Query Based Feature Selection (QBFS) is developed for selecting features to obtain a balance between the relative minimum subset of features and the relative maximum classification accuracy. Performance of the QBLS system and the QBFS algorithm is successfully demonstrated with a real-world application

A collaborative model for learning and assessment of legal placements

This paper will report on the evaluation of a new undergraduate legal workplace unit, LWB421 Learning in Professional Practice. LWB421 was developed in response to the QUT’s strategic planning and a growing view that work experience is essential to developing the skills that law graduates need in order to be effective legal practitioners (Stuckey, 2007). Work integrated learning provides a context for students to develop their skills, to see the link between theory and practice and support students in making the transition from university to practice (Shirley, 2006). The literature in Australian legal education has given little consideration to the design of legal internship subjects (as distinct from legal clinic programs). Accordingly the design of placement subjects needs to be carefully considered to ensure alignment of learning objectives, learning tasks and assessment. Legal placements offer students the opportunity to develop their professional skills in practice, reflect on their own learning and job performance and take responsibility for their career development and planning. This paper will examine the literature relating to the design of placement subjects, particularly in a legal context. It will propose a collaborative model to facilitate learning and assessment of legal work placement subjects. The basis of the model is a negotiated learning contract between the student, workplace supervisor and academic supervisor. Finally the paper will evaluate the model in the context of LWB421. The evaluation will be based on data from surveys of students and supervisors and focus group sessions.

Harmonising procurement policy environment - identifying key themes towards the development of a conceptual model

Capital works procurement and its regulatory policy environment within a country can be complex entities. For example, by virtue of Australia’s governmental division between the Commonwealth, states and local jurisdictions and the associated procurement networks and responsibilities at each level, the tendering process is often convoluted. There are four inter-related key themes identified in the literature in relation to procurement disharmony, including decentralisation, risk & risk mitigation, free trade & competition, and tendering costs. This paper defines and discusses these key areas of conflict that adversely impact upon the business environments of industry through a literature review, policy analysis and consultation with capital works procurement stakeholders. The aim of this national study is to identify policy differences between jurisdictions in Australia, and ascertain whether those differences are a barrier to productivity and innovation. This research forms an element of a broader investigation with an aim of developing efficient, effective and nationally harmonised procurement systems. Keywords: capital works, procurement policy reform Acknowledgement: The research described in this paper carried out by the Australian Cooperative Research Centre for Construction Innovation.

A model for the uptake of E-business by building small and medium enterprises

The adoption of e-business by Small and Medium Enterprises (SMEs) in construction lags from other service and product businesses within the building sector. This paper develops a model to facilitate the uptake of electronic business, especially in relation to SMEs within the Australian construction sector. Ebusiness is defined here as “the undertaking of business-related transactions, communications and information exchanges utilising electronic medium and environment”, the elicited model highlights significant changes needed including skills development, social, economic and cultural issues. The model highlights barriers for SMEs to migrate towards e-transactions, e-bidding, e-tendering and ecollaboration and provides learning and skills development components. The model is derived from case study fieldwork and is to inform diffusion and awareness models for best practice. Empirical techniques included ‘focus group’ interviews and one to one ‘interviews’. Data was transcribed and analysed using cluster analyses. Preliminary results reveal that current models for e-business adoption are not effective within the construction context as they have emerged from other service and product industries - such as retail or tourism. These generic models have largely ignored the nature of the construction industry, and some modifications appears to be required. This paper proposes an alternative adoption model which is more sensitive to the nature of the industry – particularly for e-business uptake in building SME’s.

Situated case-based reasoning as a constructive memory model for design reasoning

This paper describes an extended case-based reasoning model that addresses the notion of situatedness in designing through constructive memory. The model is illustrated through an application for predicting the corrosion rate for a specific material on a specific building.

Concurrent multi-scale modeling of civil infrastructures for analyses on structural deterioration—Part I : Modeling methodology and strategy

This paper aims to develop the methodology and strategy for concurrent finite element modeling of civil infrastructures at the different scale levels for the purposes of analyses of structural deteriorating. The modeling strategy and method were investigated to develop the concurrent multi-scale model of structural behavior (CMSM-of-SB) in which the global structural behavior and nonlinear damage features of local details in a large complicated structure could be concurrently analyzed in order to meet the needs of structural-state evaluation as well as structural deteriorating. In the proposed method, the “large-scale” modeling is adopted for the global structure with linear responses between stress and strain and the “small-scale” modeling is available for nonlinear damage analyses of the local welded details. A longitudinal truss in steel bridge decks was selected as a case to study how a CMSM-of-SB was developed. The reduced-scale specimen of the longitudinal truss was studied in the laboratory to measure its dynamic and static behavior in global truss and local welded details, while the multi-scale models using constraint equations and substructuring were developed for numerical simulation. The comparison of dynamic and static response between the calculated results by different models indicated that the proposed multi-scale model was found to be the most efficient and accurate. The verification of the model with results from the tested truss under the specific loading showed that, responses at the material scale in the vicinity of local details as well as structural global behaviors could be obtained and fit well with the measured results. The proposed concurrent multi-scale modeling strategy and implementation procedures were applied to Runyang cable-stayed bridge (RYCB) and the CMSM-of-SB of the bridge deck system was accordingly constructed as a practical application.

Concurrent multi-scale modeling of civil infrastructures for analyses on structural deteriorating—Part II : Model updating and verification

This paper is a continuation of the paper titled “Concurrent multi-scale modeling of civil infrastructure for analyses on structural deteriorating—Part I: Modeling methodology and strategy” with the emphasis on model updating and verification for the developed concurrent multi-scale model. The sensitivity-based parameter updating method was applied and some important issues such as selection of reference data and model parameters, and model updating procedures on the multi-scale model were investigated based on the sensitivity analysis of the selected model parameters. The experimental modal data as well as static response in terms of component nominal stresses and hot-spot stresses at the concerned locations were used for dynamic response- and static response-oriented model updating, respectively. The updated multi-scale model was further verified to act as the baseline model which is assumed to be finite-element model closest to the real situation of the structure available for the subsequent arbitrary numerical simulation. The comparison of dynamic and static responses between the calculated results by the final model and measured data indicated the updating and verification methods applied in this paper are reliable and accurate for the multi-scale model of frame-like structure. The general procedures of multi-scale model updating and verification were finally proposed for nonlinear physical-based modeling of large civil infrastructure, and it was applied to the model verification of a long-span bridge as an actual engineering practice of the proposed procedures.

A model for assessing and correcting project Health

Maintaining the health of a construction project can help to achieve the desired outcomes of the project. An analogy is drawn to the medical process of a human health check where it is possible to broadly diagnose health in terms of a number of key areas such as blood pressure or cholesterol level. Similarly it appears possible to diagnose the current health of a construction project in terms of a number of Critical Success Factors (CSFs) and key performance indicators (KPIs). The medical analogy continues into the detailed investigation phase where a number of contributing factors are evaluated to identify possible causes of ill health and through the identification of potential remedies to return the project to the desired level of health. This paper presents the development of a model that diagnoses the immediate health of a construction project, investigates the factors which appear to be causing the ill health and proposes a remedy to return the project to good health. The proposed model uses the well-established continuous improvement management model (Deming, 1986) to adapt the process of human physical health checking to construction project health.

Relative entropy rate based multiple hidden Markov Model Approximation

This paper proposes a novel relative entropy rate (RER) based approach for multiple HMM (MHMM) approximation of a class of discrete-time uncertain processes. Under different uncertainty assumptions, the model design problem is posed either as a min-max optimisation problem or stochastic minimisation problem on the RER between joint laws describing the state and output processes (rather than the more usual RER between output processes). A suitable filter is proposed for which performance results are established which bound conditional mean estimation performance and show that estimation performance improves as the RER is reduced. These filter consistency and convergence bounds are the first results characterising multiple HMM approximation performance and suggest that joint RER concepts provide a useful model selection criteria. The proposed model design process and MHMM filter are demonstrated on an important image processing dim-target detection problem.