Drivers and barriers to adopting relational contracting practices in public projects: Comparative study of Beijing and Sydney

When contracting parties adopt relational contracting (RC) as opposed to formal contracting stance, the construction project may achieve good outcomes. However, public projects usually face more constraints in adopting RC, as close relationships may lead to allegations of corruption. The aim of this study is to undertake a comparative analysis of drivers and barriers to adopting RC practices in public construction projects in two different markets viz. a centrally planned economy and a free market economy by investigating practices in Beijing and Sydney. The survey research design was adopted and data of public construction projects in Beijing and Sydney were collected using a structured questionnaire. The results revealed that relationship quality and level of harmony among contracting parties are significantly good in both cities. In Sydney, the level of inter-personal relations between contractors and consultants is significantly higher than in Beijing. It was found that the same 18 factors drive contracting parties in Beijing and Sydney to adopt RC practices, and in 6 instances, these are significantly greater drivers in Sydney. The barriers to adopting RC practices are totally dissimilar in both cities. Contracting parties in Beijing could not adopt more RC practices because of a lack of training in relational arrangement and public clients lack initiative in adopting RC practices. The conservative industry culture that encourages preservation of the status quo is also prevalent in Beijing. In Sydney, the only significant barrier is public sector accountability concerns. To cultivate readiness to embrace RC practices, it is suggested that industry professionals and the government adopt recommendations highlighted in this study according to the type of market structure.     

城市更新视角下纽约历史街区保护更新模式研究 ——以格林威治村历史街区为例

随着我国城市进入城镇化“下半场”, 城市发展的范式产生转变,历史街区价值逐渐 显现,历史街区的保护与更新成为城市更新进程 中的重要类型。本文聚焦纽约历史街区保护更 新模式的研究,以纽约格林威治村历史街区为 研究案例,探讨了20世纪60年代纽约市《城市 地标保护法》出台后,纽约市应对不同尺度、不 同类型历史街区保护更新项目的模式机制。研究 以历史街区的保护更新项目为对象,从历史街区 遗产价值与更新模式相互关联的维度,梳理历 史街区的发展背景和空间演化过程,解析了历史 街区的层积性的历史价值、活态化的文化遗产和 多样性的美学特征,详细阐释了应对历史文化传 承和城市更新发展双重目标导向下,纽约历史街 区从建筑单体到街区,不同尺度、不同类型项目 的保护更新模式机制。     

Simultaneous removal of carbon and nutrients from an industrial estate wastewater in a single up-flow aerobic/anoxic sludge bed (UAASB) bioreactor

Simultaneous removal of carbon and nutrients (CNP) in a single bioreactor is highly significant for energy consumption and control of reactor volume. Basically, nutrients removal is dependant to the ratio of biochemical oxygen demand to chemical oxygen demand (BOD₅/COD). Thus, in this study the treatment of an industrial estate wastewater with low BOD₅/COD ratio in an up-flow aerobic/anoxic sludge bed (UAASB) bioreactor, with an intermittent regime in aeration and discharge, was investigated. Hydraulic retention time (HRT) of 12-36 h and aeration time of 40-60 min/h were selected as the operating variables to analyze, optimize and model the process. In order to analyze the process, 13 dependent parameters as the process responses were studied. From the results, it was found, increasing HRT decreases the CNP removal efficiencies. However, by increasing the BOD₅ fraction of the feed, the total COD (TCOD), slowly biodegradable COD (sbCOD), readily biodegradable COD (rbCOD), total nitrogen (TN), and total phosphorus (TP) removal efficiencies were remarkably increased. Population of heterotrophic, nitrifying and denitrifying bacteria showed good agreement with the results obtained for TCOD and TN removal. The optimum conditions were determined as 12-15 h and 40-60 min/h for HRT and aeration time respectively.     

老城区社区生活圈测度及公共服务设施优化研究 ——以宜宾市为例

在我国城镇化的下半场,以人为本、存 量规划和集约发展成为当下城市的主旋律,作 为承载城市记忆的老城区社区生活圈亟待更新 优化。以宜宾市老城组团为例,采用连锁网络模 型和基于真实路网的设施可达性分析等方法,结 合10大类公服设施POI数据、当地居民对设施的 重要性评价数据,对研究区域进行了10分钟社 区生活圈的测度探索,并在测度结果的基础上, 以生活圈为视角提出了相应公服设施的优化及 择址建议。研究结果表明：第一,宜宾老城共可 划定出4个10分钟社区生活圈,平均用地规模较 小于平原、省会、特大型城市;第二,4个生活圈 整体都存在公园广场、社会福利、科教文化这3 类设施数量较为欠缺及覆盖范围较小的共性问 题;第三,各生活圈生活便利度差异明显,发展不均衡。未来宜侧重优化过渡区、边缘生活圈欠缺设施;第四,基于设施覆盖率及居民可达程度 考虑,每个生活圈宜提供中心度前三的地块中心点作为10分钟层级设施的推荐设置点。     

公共健康视角下城市社区绿道空间挖掘与规划选线研究 ——以苏州市中心城区为例

社区绿道作为基层公共健康单元的重 要组成部分,发挥支持人群活动、服务日常生 活、促进身心发展的效用。在后疫情背景下,研 究聚焦社区绿道选线问题,以苏州市中心城区 为案例区,从解读公共健康与社区绿道关系入 手,明晰公共健康视角下社区绿道,在集聚人群 活动、连接便捷服务、提供舒适环境的效能的 基础上,运用热力图叠加分析、POI数据核密度 计算、载体空间适建性评价等技术手段,展开社 区绿道出行活力度、目的地潜力度、载体适建性的综合评价,以充分挖掘促进“生理—心理—社会”健康综合提升的社区绿道选线及方案,以推 进健康中国建设,增进人民健康福祉。     

Whites' neighbourhood racial preferences and neighbourhood racial composition in the United States: evidence from the multi‐city study of urban inequality

Within the housing segregation literature major disagreements have developed over two fundamental issues: (1) the role that whites' aversion to racially mixed neighbourhoods plays in causing modern segregation in the US; and (2) the factors that underlie this aversion, including the effects of inter‐racial contact on whites' neighbourhood racial preferences and whether these preferences reflect neighbourhood stereotyping as opposed to pure racial prejudice. Extant evidence on these issues is either old or indirect. This paper provides direct evidence on these issues using new data from the Multi‐City Study of Urban Inequality. The results suggest that (1) whites' neighbourhood racial preferences play an important role in explaining the racial composition of their neighbourhoods; (2) inter‐racial contact in neighbourhoods and workplaces leads to a greater willingness among whites to live with blacks; and (3) although younger and more educated whites express a stronger taste for integration than other whites, the magnitude of these differences leads to only a small increase in the black percentage of the neighbourhood. In addition, the results provide no evidence in support of the hypothesis that whites stereotype black neighbourhoods rather than blacks per se.     

Coupled HM effects in a crystalline rock mass due to glaciation: indicative results from groundwater flow regimes and stresses from an FEM study

This paper highlights certain aspects of glacial impact on groundwater flow and rock mechanics, of particular interest in future scenarios for the geological disposal of nuclear waste. The investigation took the form of a generic exercise based on conditions at the underground research facility in Whiteshell, Canada. The site scale model domain boundaries were set up based on a number of major deformation zones. The surface boundary conditions comprised a transient ice sheet load and related hydraulic heads, generated by meltwater. It has thus been possible to compare glacial impact in relation to present-day climatological conditions. The main issues in the investigation were to evaluate the groundwater flow regime and the pre-requisites for underground jacking as well as shearing according to the prescribed geoscientific properties of a benchmark protocol. Special attention has been devoted to a solution to the hydromechanical (HM) problem (1) with or without process coupling, (2) with or without a transient approach, and (3) considering a two- or three-dimensional mode. The study underlines the need for transient analyses in 3D of these coupled phenomena.