Investigating the client-related rework in building projects: The case of Singapore

Rework has become one of the most common concerns in construction projects. This study aims to investigate the client-related rework (CRR) in Singapore-based building projects. To achieve the objectives, a literature review and questionnaire survey was conducted and data were collected from 381 projects performed by 51 companies. The results confirmed that the client contributed most to rework. 41 of the 51 companies (80.4%) experienced CRR, and 226 of the 381 projects (59.3%) experienced CRR, which increased project cost by 7.1% and caused 3.3 weeks' delay on the average. Additionally, “replacement of materials by the client” was the cause with the highest frequency of occurrence, while “change of plans or scope by the client” contributed most to CRR and exerted most impact on project cost, schedule and quality performance. This study expands the literature and provides an in-depth understanding of the CRR in Singapore for both practitioners and researchers.     

从现代视角解析巴渝传统观演空间*

本文以巴渝传统观演空间为例,从现代视角解析传统空间营造手法,探索传统观演空间模式语言。从观演空间的平面布局、功能组合、营建技术及光线和声音的处理等方面,结合现代剧场建筑的基础理论,分析传统观演空间在现代建筑活动中的优势,初步探索观演空间回归传统的可行性,以期传承传统观演空间的营造精髓和把握观演关系的意境。     

A primer on the building economics of climate change

Climate change will entail new conditions for the construction industry. Knowledge about the implications of climate change on the built environment will be of the utmost importance to the industry in years to come. A building is a ‘long lasting’ durable asset that is changed over time due to exogenously imposed strains and by actions. The built environment has an expected lifetime varying from 60 to more than 100 years. Hence, the building economics of climate change should be treated within a dynamic analytical framework that explicitly allows for changes in the information sets over time. The building stock of the future consists of the building stock of today and of new construction. In the future, parts of the present building stock will be adapted to changes in the environment, while some parts will be kept as they are. Analysis of how building stock is affected by future climate change should handle this diversity. This can be done through the use of a putty-clay model. Uncertainty of what kind of climate regimes will prevail in the future enhances the profitability of actions that increase future flexibility. Hence, the real option approach to building economics is utilized.     

Indicators for measuring construction industry development in developing countries

The problems of construction industries in developing countries are well researched. For over three decades, proposals have been made for action to address these difficulties. Developing countries have implemented these recommendations, and other initiatives. However, results have been disappointing and the problems have persisted. A possible reason for the lack of progress is the absence of measurable targets in construction industry development programmes to guide and assess, at intervals, the success of their implementation. This paper critically discusses the formulation of a set of indicators for measuring and monitoring progress in the effort to improve the construction industry in a developing country. Previous proposals of indicators and those used in Singapore are examined. A set of indicators is suggested and their merits and possible problems are considered. Recommendations are made on how the indicators can be most effectively implemented.

Les problèmes liés à l'industrie du bâtiment dans les pays en voie de développement sont clairement définis. Pendant plus de trois décennies, des propositions ont été formulées en vue de mener des actions visant à surmonter ces difficultés. Les pays en voie de développement ont suivi ces recommandations et pris d'autres initiatives. Néanmoins, les résultats ont été décevants et les problèmes ont persisté. L'une des raisons possibles du manque d'avancée est l'absence d'objectifs mesurables dans les programmes de développement de l'industrie du bâtiment, qui permettraient de guider et d'évaluer, par intervalles, la réussite de leur mise en oeuvre. Le présent document aborde de façon critique la formulation d'un groupe d'indicateurs destinés à mesurer et à surveiller la progression des efforts destinés à améliorer l'industrie du bâtiment dans un pays en voie de développement. Il examine également les propositions antérieures relatives à des indicateurs, ainsi que celles utilisées à Singapore. Il suggère enfin un groupe d'indicateurs et examine leurs avantages et leurs inconvénients éventuels. Des recommendations visant à optimiser l'utilisation de ces indicateurs sont également formulées.     

A HUMAN RELIABILITY ANALYSIS OF REINFORCED CONCRETE BEAM CONSTRUCTION

A significant proportion of performance failures (e.g., structural failure, cost overruns, delays) are due to human error in the construction of in-situ reinforced concrete elements. A Human Reliability Analysis (HRA) model has been developed to simulate the effect of human error on the construction of a reinforced concrete beam. The proposed HRA model incorporates the effect of (i) initial errors (i.e., before engineering inspections) and (ii) errors remaining after engineering inspections. The following typical construction tasks are considered: number and size of reinforcing bars, effective depth of steel reinforcing, beam width, and quality of concrete mix. Human performance models are described for each of these microtasks. It was found that human error leads to a significant loss of structural safety. It was also shown that engineering inspections significantly increased structural reliability, but the resulting structural reliability was still an order of magnitude lower than "nominal" estimates of structural reliability.     

Intra-team boundaries as inhibitors of performance improvement in UK design and build projects: a call for change

The success of the design and build (D&B) procurement route could be undermined by issues arising from the rigid professional cultures of individual participants within project workgroups. These have the potential to inhibit the achievement of a key espoused benefit of D&B procurement, i.e. that it promotes the integration of the design and construction processes for improved project performance. Cultural non-interoperability is identified as a significant potential barrier to effective change management, and to the achievement of innovation within the design and construction processes. This note argues that project responsibilities, which currently are delineated along professional identity lines, produce design and construction solutions that fail to fulfil the potential of D&B procurement. It is suggested that addressing cultural interoperability will require a fundamental and long term reshaping of the industry's structure, beginning with the professional bodies and the higher education system that underpins their future membership.     

厦门国际艺术品（金融）交易中心结构分析与设计

厦门国际艺术品（金融）交易中心采用了钢管混凝土框架柱＋钢梁-钢筋混凝土核心筒的混合结构体系,为具备扭转不规则、穿层柱、塔楼偏置等问题的超限高层。针对工程特点,主要探讨了从结构布置、构造措施、性能目标、整体计算和节点设计等方面对主楼所采取的加强措施,并进行了静力弹塑性分析。结果表明,各项指标均较理想,整体设计满足设计的性能目标。     

钢筋自密实混凝土梁受剪性能试验研究及分析

自密实混凝土工程应用逐渐增多,为研究钢筋自密实混凝土梁的受剪性能,进行了4根钢筋自密实混凝土梁试件和2根普通钢筋混凝土梁试件的试验,研究自密实混凝土梁受剪性能的破坏形态、开裂荷载、裂缝发展和抗剪承载力,并且将其与普通钢筋混凝土梁作对比分析。将试验值与 GB 50010-2010《混凝土结构设计规范》计算的理论值与相比较。结果表明,竖向集中荷载作用下,钢筋自密实混凝土梁与普通钢筋混凝土梁有着相似的破坏特征与承载能力。钢筋自密实混凝土梁理论值与试验值的比为0.59,比普通钢筋混凝土梁理论试验值的比值高出0.11。     

同塔多回输电线路杆塔可靠指标及失效概率分析

输电线路杆塔结构可靠指标及失效概率的分析研究,目前已经广泛应用于实际工程当中,本文着重研究了500kV同塔四回输电线路杆塔的可靠指标及失效概率。对于风荷载占控制因素的杆塔结构,本文研究了可靠指标计算参数组合对于杆塔失效概率的影响,同时计算了500kV同塔四回典型杆塔的可靠指标及失效概率,提出基于输电杆塔可靠度理论的杆塔风险规避的建议。     

废旧钢纤维橡胶再生混凝土短柱受力性能试验研究

本文以再生骨料取代率和偏心距两个参量作为变量,完成了4根的轴心受压和6根偏心受压废旧橡胶钢纤维再生混凝土短柱试验。对构件的受压性能进行了研究和分析,结合《混凝土设计规范》（GB50010—2010）相关条款,探讨规范对废旧橡胶钢纤维再生混凝土短柱承载力的适用性。试验结果可为其工程应用提供参考。