Wind-resistant low-rise buildings in the tropics

High-wind events such as storms and hurricanes cause severe damage to low-rise building (housing, schools, and industrial, commercial, and farm buildings). Roof claddings often suffer the worst, which then leads to accelerated damage to the whole building. Australia leads the way in solving this international problem through extensive research and development work, and has adequate documents in place. This paper first illustrates briefly the nature of high-wind events and then the commonly observed damage to buildings. Australian research work and design practice are then described, based on which suitable design recommendations for wind-resistant buildings are presented.

Three-dimensional modeling of steel portal frame buildings

The realistic strength and deflection behavior of industrial and commercial steel portal frame buildings are understood only if the effects of rigidity of end frames and profiled steel claddings are included. The conventional designs ignore these effects and are very much based on idealized two-dimensional (2D) frame behavior. Full-scale tests of a 1212 m steel portal frame building under a range of design load cases indicated that the observed deflections and bending moments in the portal frame were considerably different from those obtained from a 2D analysis of frames ignoring these effects. Three-dimensional (3D) analyses of the same building, including the effects of end frames and cladding, were carried out, and the results agreed well with full-scale test results. Results clearly indicated the need for such an analysis and for testing to study the true behavior of steel portal frame buildings. It is expected that such a 3D analysis will lead to lighter steel frames as the maximum moments and deflections are reduced.

Achieving world leadership in sustainable buildings - a Brisbane case study

In Australia, the building and construction industry is taking significant steps towards the enhancement of environmental performance of the built environment. A large number of world class sustainable buildings have been constructed in recent years, offering researchers and practitioners alike a good opportunity to identify the best practices and real life experiences in delivering high performance buildings. A case study of ONE ONE ONE Eagle Street, a 6 Star Green Star office building in Brisbane, was conducted to investigate the best practice in achieving this “world leader” green office building. The study identified a number of key factors relating to project delivery system, contractor selection method, client’s early commitment, design integration, communication as major contributors to the successful delivery of this project. Additionally, key environmentally sustainable features and their cost implications were explored through in-depth interviews with the main contractor. The findings of this study will shed lights on the successful delivery of sustainable buildings and provide practical implications for different stakeholders.

Reflections on chemistry sessions at the 2012 Healthy Buildings Conference

Scores of well-researched individual papers and posters specifically or indirectly addressing the occurrence, measurement or exposure impacts of chemicals in buildings were presented at 2012 Healthy Buildings Conference. Many of these presentations offered advances in sampling and characterisation of chemical pollutants while others extended the frontiers of knowledge on the emission, adsorption, risk, fate and compositional levels of chemicals in indoor and outdoor microenvironments. Several modelled or monitored indoor chemistry, including processes that generated secondary pollutants. This article provides an overview of the state of knowledge on healthy buildings based on papers presented in chemistry sessions at Healthy Buildings 2012 (HB2012) Conference. It also suggests future directions in healthy buildings research.

Buildings : Climate Change

The cycling interaction between climate change and buildings is of dynamic nature. On one hand, buildings have contributed significantly to the process of human‐induced climate change. On the other hand, climate change is also expected to impact on many aspects of buildings, including building design, construction, and operation. In this entry, these two aspects of knowledge are reviewed. The potential strategies of building design and operation to reduce the greenhouse gas emissions from buildings and to prepare the buildings to withstand a range of possible climate change scenarios are also discussed.

Exploring influencing factors of short-lived buildings in China's urban renewal : evidence from Chongqing

With the fast development of urban sprawl and renewal in China, many buildings are “non-nature” short-lived, i.e. demolished after only a few years. For this concern, this research explores the influencing factors of short-lived buildings and provides the scientific foundation for sustainable urban management and planning. Cases for this research are 1734 buildings demolished in Jiangbei district, the middle region of Chongqing City. Internal and external factors for the short-lived buildings are identified by applying logistic analysis. The results indicate that nine factors have significant influence on short-lived buildings. This research also find that buildings with low density, utilization and compensation while high land development potential are more likely to become short-lived buildings.

Developing sustainable ‘liveable’ buildings, cities and communities for a sub-tropical context : residents’ perspectives

A key challenge for the 21st Century is to make our cities more liveable and foster economically sustainable, environmentally responsible, and socially inclusive communities. Design thinking, particularly a human-centred approach, offers a way to tackle this challenge. Findings from two recent Australian research projects highlight how facilitating sustainable, liveable communities in a humid sub-tropical environment requires an in-depth understanding of people’s perspectives, experiences and practices. Project 1 (‘Research House’) documents the reflections of a family who lived in a ‘test’ sustainable house for two years, outlining their experience and evaluations of universal design and sustainable technologies. The study family was very impressed with the natural lighting, natural ventilation, spaciousness and ease of access, which contributed significantly to their comfort and the liveability of their home. Project 2 (‘Inner-Urban High Density Living’) explored Brisbane residents’ opinions about high-density living, through a survey (n=636), interviews (n=24), site observations (over 300 hours) and environmental monitoring, assessing opinions on the liveability of their individual dwelling, the multi-unit host building and the surrounding neighbourhood. Nine areas, categorised into three general domains, were identified as essential for enhancing high density liveability. In terms of the dwelling, thermal comfort/ventilation, natural light, noise mitigation were important; shared space, good neighbour protocols, and support for environmentally sustainable behaviour were desired in the building/complex; and accessible/sustainable transport, amenities and services, sense of community were considered important in the surrounding neighbourhood. Combined, these findings emphasise the importance and complexity associated with designing liveable building, cities and communities, illustrating how adopting a design thinking, human-centred approach will help create sustainable communities that will meet the needs of current and future generations.

Discomfort glare in open plan green buildings

This study presents the largest-known, investigation on discomfort glare with 493 surveys collected from five green buildings in Brisbane, Australia. The study was conducted on full-time employees, working under their everyday lighting conditions, all of whom had no affiliation with the research institution. The survey consisted of a specially tailored questionnaire to assess potential factors relating to discomfort glare. Luminance maps extracted from high dynamic range (HDR) images were used to capture the luminous environment of the occupants. Occupants who experienced glare on their monitor and/or electric glare were excluded from analysis leaving 419 available surveys. Occupants were more sensitive to glare than any of the tested indices accounted for. A new index, the UGP was developed to take into account the scope of results in the investigation. The index is based on a linear transformation of the UGR to calculate a probability of disturbed persons. However all glare indices had some correlation to discomfort, and statistically there was no difference between the DGI, UGR and CGI. The UGP broadly reflects the demographics of the working population in Australia and the new index is applicable to open plan green buildings.

Optimisation of lateral load-resisting systems in composite high-rise buildings

This research is carried out by using finite element modelling of building prototypes with three different layouts (rectangular, octagonal and L-shaped) for three different heights (98.0 m, 147.0 m and 199.5 m) for the optimization of lateral load-resisting systems in composite high-rise buildings. Variations of lateral bracings (different number and varied placement along model height of belt-truss and outrigger floors) with RCC (reinforced cement concrete) core wall are used in composite high-rise building models. Prototypes of composite buildings are analysed for dynamic wind and seismic loads. The effects on serviceability (deflection and frequency) of models are studied and conclusions are deduced.

Vulnerability and damage analysis of reinforced concrete framed buildings subjected to near field blast events

Terrorists usually target high occupancy iconic and public buildings using vehicle borne incendiary devices in order to claim a maximum number of lives and cause extensive damage to public property. While initial casualties are due to direct shock by the explosion, collapse of structural elements may extensively increase the total figure. Most of these buildings have been or are built without consideration of their vulnerability to such events. Therefore, the vulnerability and residual capacity assessment of buildings to deliberately exploded bombs is important to provide mitigation strategies to protect the buildings' occupants and the property. Explosive loads and their effects on a building have therefore attracted significant attention in the recent past. Comprehensive and economical design strategies must be developed for future construction. This research investigates the response and damage of reinforced concrete (RC) framed buildings together with their load bearing key structural components to a near field blast event. Finite element method (FEM) based analysis was used to investigate the structural framing system and components for global stability, followed by a rigorous analysis of key structural components for damage evaluation using the codes SAP2000 and LS DYNA respectively. The research involved four important areas in structural engineering. They are blast load determination, numerical modelling with FEM techniques, material performance under high strain rate and non-linear dynamic structural analysis. The response and damage of a RC framed building for different blast load scenarios were investigated. The blast influence region for a two dimensional RC frame was investigated for different load conditions and identified the critical region for each loading case. Two types of design methods are recommended for RC columns to provide superior residual capacities. They are RC columns detailing with multi-layer steel reinforcement cages and a composite columns including a central structural steel core. These are to provide post blast gravity load resisting capacity compared to typical RC column against a catastrophic collapse. Overall, this research broadens the current knowledge of blast and residual capacity analysis of RC framed structures and recommends methods to evaluate and mitigate blast impact on key elements of multi-storey buildings.

Improving the penetration level of PVs using DC link for residential buildings

This paper proposes the use of a common DC link in residential buildings to allow customers to inject their surplus power that otherwise would be limited due to AC power quality violation. The surplus power can easily be transferred to other phases and feeders through common DC link in order to maintain the balance between generated power and load. PSCAD-EMTDC platform is used to simulate and study the proposed approach. This paper suggests that this structure can be a pathway to the future DC power systems.

Are lifecycle funds appropriate as default options in participant-directed retirement plans?

The appropriateness of default investment options in participant-directed retirement plans like 401(k) has been in sharp focus given that most participants fail to nominate an investment option to direct their contributions. In United States (US), prior to the Pension Protection Act (PPA) of 2006, plan fiduciaries often selected a money market fund as the default option. Whilst this ‘low risk and low return’ investment option was considered to be a ‘safe’ choice by many fiduciaries who were fearful of litigation risk, it was heavily criticized for resulting in inadequate wealth at retirement, particularly when retirees were living much longer and facing inflation risk (see, for example, Viceira, 2008; Skinner, 2009)...

The Performance Nexus - A framework for improving energy efficiency in existing commercial buildings by considering a whole-of-building approach

Efforts to reduce carbon emissions in the buildings sector have been focused on encouraging green design, construction and building operation; however, the business case is not very compelling if considering the energy cost savings alone. In recent years green building has been driven by a sense that it will improve the productivity of occupants,i something with much greater economic returns than energy savings. Reducing energy demand in green commercial buildings in a way that encourages greater productivity is not yet well understood as it involves a set of complex and interdependent factors. This paper outlines an investigation into these factors and focuses on better understanding the performance of and interaction between: design elements, internal environmental quality, occupant experience, tenant/leasing agreements, and building regulation and management. In doing so the paper presents a framework for improving energy efficiency in existing commercial buildings by considering a range of interconnected and synergistic elements.