房建工程中混凝土结构碳化的定量分析

利用多场耦合数值模型,对房建工程中的粗骨料取代率、环境温度、相对湿度和二氧化碳浓度等因素进行定量分析。结果表明,当房屋建筑是处于一种高温环境并且密封状态下的情况下,就会极大程度的引起建筑工程材料中碳化问题,而碳化发生几率中处于高温环境但是通风状况良好的房屋建筑次之,低温室外环境碳化程度最轻微。影响混凝土结构服役寿命的重要因素包括环境温度、粗骨料取代率、环境相对湿度。当相对湿度和粗骨料取代率一定时,粗骨料混凝土结构的使用寿命会伴随着房屋的内部温度的升高而出现降低的趋势;相比于二维碳化的情况而言,出现一维碳化现象的粗骨料混凝土结构的房屋建筑的使用寿命大约是二维碳化情况下的两倍。碳化速率系数的限值会伴随着房屋建筑设计使用年限的不断增加而呈现负相关趋势;即所有影响因素都基本保持一致的情况下,房屋建筑工程中混凝土的保护层的厚度越大的时候,就会加速碳化速率的系数限值;环境系数越大的时候,碳化速率系数限值就呈现负相关递减趋势,并且变化幅度较为显著。     

Benchmarking project performance: a guideline for assessing vulnerability of mechanical and electrical projects to productivity loss

Loss of productivity is a contentious issue that has a profound impact on modern construction, yet existing literature provides no quantitative, data-driven method to compare the productivity of different construction projects or to assess their vulnerability to productivity loss. A new mathematically derived metric, called the “Risk of Productivity Loss (RPL)” score, provides such a method. RPL is a function of multiple distinct productivity factors. The RPL score is developed from a dataset of 166 electrical and mechanical projects, which collectively amount to 7.2 million labour hours. This large sample size makes the RPL score a reliable productivity benchmark for the electrical and mechanical construction industries due to their labour-intensive nature. The higher the RPL score, the higher the risk that a given project will suffer from productivity losses. To supplement the mathematical formula presented, objective data-based weights for multiple key productivity factors have been identified, reducing the subjectivity that affects many of the existing weighting assessment methods. RPL provides the industry with a single metric that allows tracking and assessment of productivity for multiple projects at a time so that a contractor may assess the successful reduction of productivity risk factors within the projects in their company.     

Improving decision-making in maintenance policies and contract specifications for infrastructure projects

In large infrastructure projects, the government frequently delegates the execution and management to a private through Public–Private Partnerships (PPP) type contract. However, both parties often have conflicting interests; i.e. while the private wants to maximise the profit, the government aims at maintaining a high-performance level. This paper presents a model to define a set of contract parameters that maximise the utility of both entities in the long term, and at the same time optimise the system performance. Moreover, it proposes a strategy for the private to decide the optimal maintenance frequencies and achieve its target revenue. It also describes the complex interactions between the public, the private and nature (i.e. all environmental aspects that influence the system’s performance). The model combines the advantages game theory, simulation, optimisation and agent-based modeling. A set of 72 types of Build-Operate-Transfer (BOT) contracts are simulated, with a sensitivity analysis on the main contract variables (i.e. minimum level of performance required, mean frequency of government inspections, and penalty fee in case of noncompliance). The results show the importance of flexibility in decisions when facing different sources of uncertainty, and in reducing information asymmetry between the parties to improve maintenance decisions.     

基坑工程风险的定量分析初探

总结近年来基坑工程风险分析中存在的一些问题,分析了基坑工程风险的一些基本特性,统计了上海与全国在不同历史阶段基坑工程风险案例的一般规律并做了深入的分析。最后初步提出了根据基坑工程风险的特性进行风险分析的一个理论模型。     

Use of risk analysis in North Sea projects

Risk analysis, as applied to North Sea oil projects, is described. Two projects in particular are presented as examples: the Murchison and Hutton fields. The unpredictable North Sea weather conditions make risk analysis particularly suited to these projects. The advantages of the technique are outlined, along with some of its disadvantages.     

港岛建设项目人为影响因素的定量分析

首先从定性的角度进行了项目建设人为因素分析，然后基于主成分分析法，提出定量分析模型，最后以某港岛建设为例进行了实例计算，结果表明，管理风险和合同风险是港岛项目建设的关键，应该给予特别的关注。     

建筑工程项目风险分析与控制

对建筑工程项目风险的概念、特点、分类进行了介绍,并对建筑工程项目风险进行了分析,提出了建筑工程项目风险的控制措施,以期能够对风险进行合理的分析和有效的控制与管理,从而确保项目的质量。     

高校基建工程优化管理研究

分析了高校基建的特点和重要性，针对目前高校基建的管理形式，探讨了优化管理的思路和途径，从前期论证，过程管理，结算审计等环节进行了论述，以保证基建工程的健康良性发展。     

建筑工程项目施工中的风险管理

阐述了施工中引入风险管理的重要性，探讨了建筑工程项目施工中的风险分类、识别及分析与控制方法，介绍了施工企业风险管理制度的建立措施，以增强项目的抗风险能力，提高企业的风险管理水平。     

简述工程项目的风险管理

针对我国目前工程建设项目前期忽视或不重视风险管理的现状,从风险管理的基本理论出发,介绍了风险管理的组织和程序及风险的分类,深入探讨了工程项目风险分析与控制方法,提出了一些工程项目风险控制的具体措施。     

建筑工程项目建设阶段中的风险管理探讨

阐述了风险管理的发展及经济、社会意义,指出现阶段条件下建筑工程项目风险管理中存在的若干问题,并对建筑工程项目风险应对措施做了系统的论述,以期提高企业竞争力和经营水平。     

A domain ontology for construction concepts in urban infrastructure products

Domain ontologies are the cornerstone of informatics systems. Like their philosophical counterparts, they aim at providing a shared representation (language) for the concepts within a domain of knowledge. Ontologies are related more to knowledge representation rather than reasoning. Consequently, they normally can be complemented by artificial intelligence tools to enhance their decision support capabilities. This paper presents an ontology that is an abstract (yet extendable) philosophical (yet practical) conceptualization of the essence of knowledge that relates to construction aspects of infrastructure products. A product is the outcome of any work process and includes physical products, decisions, abstract knowledge and knowledge items generated based on all of these. A set of related constraints, mechanism, actors and process are identified along with these products. Product attributes and modalities are also presented to help describe the behavior of these products and support the generation of types or classes of these products.     

Organization and governance in construction

Transaction cost analysis provides a viable theoretical perspective for the study of organization and governance in construction. The trilateral governance of a client, engineering consultant, and contractors commonly observed in industrial construction projects is detailed. The implications of a professional relationship between the client and the consultant and a clan-type relationship between the consultant and the contractors are discussed within the context of large construction projects.     

地铁综合体建设后建线路工程的风险研究

后建地铁线路工程与先建线路相比具有较高的风险性,为了正确评价后建地铁工程中的风险点,通过风险辨识、风险估计、风险处理等分析流程,对后建地铁线路工程的风险提出相应的处理措施,以保证后建地铁线路工程的安全.     

Critical success factors for PPP/PFI projects in the UK construction industry

Public–private partnerships (PPPs) are increasingly used in the United Kingdom's public facilities and services provision through the Private Finance Initiative (PFI). Despite some casualties, PPP/PFI projects have been undertaken successfully, but the reasons for success are not entirely clear. Questionnaire survey research examined the relative importance of 18 potential critical success factors (CSF) for PPP/PFI construction projects in the UK. The results show that the three most important factors are: ‘a strong and good private consortium’, ‘appropriate risk allocation’ and ‘available financial market’. Factor analysis revealed that appropriate factor groupings for the 18 CSFs are: effective procurement, project implementability, government guarantee, favourable economic conditions and available financial market. These findings should influence policy development towards PPPs and the manner in which partners go about the development of PFI projects.     

Time and cost securing in complex large-scale projects

Meeting time and cost objectives in complex projects involves specific problems and risks. An attempt is made to analyse the components of total cost increase of a project caused by time delay. An outline is given as to how these considerations can be used to estimate cost increases in investors' decision situations as well as to ascertain fair contractual penalties and claims for compensation and for the evaluation of justified project acceleration costs.     

Perceptions of owners in German construction projects: congruence with project risk theory

The construction industry is a major user of formal project risk management practices, yet risk is often dealt with inadequately, which is a contributory factor to poor performance. Conceptual developments propose a holistic view of risk incorporating threats and opportunities and the management of uncertainty. To optimize a risk management process there needs to be a reflection of this holistic view in management practice. A key project participant is the owner and understanding the perceptions of project risk of construction owners is an important step in assessing the degree to which practices reflect theory. Semi‐structured interviews were conducted with 10 practitioners in German construction owner organizations to explore their perceptions of project risk. The results showed no common definition of project risk and a general belief that risk equated to threat. Some owners did manage opportunities and saw a link between threats and opportunities, yet this practice seemed more the result of experience than an awareness that it was an integral part of a theoretical risk management framework. Most owners perceived risk to encompass uncertainty and the sources of uncertainty perceived as most important were those linked to a longer timescale, such as the ability to let out buildings.     

电力工程总承包中的风险管理研究

通过论述加强电力建设工程风险管理的必要性,对工程合同存在的风险、设计风险、政策法律风险、质量风险、财务风险等进行了分析,并提出了合理的管理对策,以有效降低电力总承包中的风险。     

工程项目施工成本管理分析

简要介绍了工程项目施工成本的概念,并从当前工程项目施工过程所存在的问题出发,提出了优化施工成本管理的可行办法,以提升企业总体管理水平,减少企业发展过程中的阻碍,最终实现经济效益和社会效益的双丰收。     

Electronic document management systems and the management of UK construction projects

The authors indicate that EDMS will not replace, but complement existing facilities and thereby enhance the management of documentation within construction organizations. It is hoped that client confidence and satisfaction can be enhanced by better communication.