An economic loss model for failure of sewer pipelines

Estimating the costs of failure for sewer pipelines is usually accompanied with uncertainties because of the difficulty in capturing the relationship between the physical and economical characteristics of failed pipelines. To reduce such uncertainties economic loss models are usually used to evaluate the consequences of failure. This paper presents a methodology to estimate economic loss as a result of sewer pipelines’ failure using cost benefit analysis approach. Costs of sewer pipelines’ failure in addition to costs resulting from avoiding such failures are identified and analysed. To validate the proposed methodology, actual costs from a real failure incident were compared with the proposed model outputs. The model could estimate the direct and indirect costs with a deviation ranging between 10–12% and 22–30%, respectively. By implementing the proposed methodology on two case studies, it was found that the indirect costs as a result of sewer pipelines’ failure represent a significant portion ranging between 89 and 94% of the total costs of failure. Also, it was found that costs related to environment, delays to work and traffic disruptions contribute by 12–35% to the indirect costs.     

An analysis of evacuation travel paths on stair landings by means of conditional probabilities

This paper analyses data on occupants׳ movement on stair landings collected during an evacuation drill performed in a six-storey office building in the United States. A total of 215 occupant travel path trajectories were filmed and time on the stair landings and egress behaviours were analysed. Data were analysed using a probabilistic approach, i.e., the probability of different occupant travel paths were calculated in relation to two different factors: (1) crowding on the landings, and (2) the type of interactions between occupants (e.g., merging flows, deference/overtaking behaviours, etc.). Results showed that a higher number of occupants on stair landings caused an increase in the probability for (1) longer travel paths and (2) usage of the outer boundaries on the stair/landing connections. This paper highlights that data and modelling assumptions should be used after a careful evaluation of their field of applicability. In the case of a low occupant load and non-homogenous merging streams (a higher number of people entering the landing from the stairs than the door), floors tend to be emptied from the top to the bottom.     

冷热电三联供系统研究(3):经济分析

介绍了燃气冷热电三联供系统的主要经济指标的定义和计算方法,通过工程实例给出了一个典型区域燃气冷热电三联供系统的具体经济参数,分析了主要不确定因素的影响;指出了国内燃气CCHP系统经济分析中存在的主要问题.     

城乡火灾风险与社会性指标的关联性研究

为探究社会性因素对城乡火灾风险的影响权重,基于火灾历史数据计算GDP、常住人口和受教育程度等指标与城乡火灾风险的关联性.计算分析发现,GDP总量与火灾数量呈现正相关关系,在省份维度GDP总量与火灾数量呈现强相关,在城市维度GDP总量与火灾数量呈现中等相关;各省常住人口与本省火灾数量呈现强相关关系,但经济欠发达省份的关联...     

公路工程环境经济损失风险多级变权模糊评价

建立影响公路工程环境经济损失的风险指标体系,提出模糊综合评价方法评价公路工程环境经济损失风险,运用惩罚与激励相结合的局部变权法计算变权重,应用实例验证了该方法的有效性和可行性。     

Mechanical investigation of tunnels: risk analysis and notation system

The current mechanical investigation strategy applied to RATP (Régie Autonome des Transpots Parisiens) tunnels is mainly based on visual inspection. All the works are inspected and every apparent fault is located and reported in inspection reports. However, this type of inspection detects only apparent faults without linking them to their causes. A new methodology of mechanical investigation is proposed in the framework of the ANR project MEDITOSS (Méthodologie de Diagnostic des Tunnels et Ouvrages Souterrains en Service), consisting in integrating mechanical investigation tools to better characterise the geometrical and mechanical state of the tunnel. This new strategy combines four techniques (ground penetrating radar, light dynamic penetrometer, endoscopy and geo-mechanical impedance). These techniques are applied to panels to obtain a ‘panel score’. This paper presents a risk analysis of the system studied (network of corridors and tunnels), by applying the bow-tie method in order to obtain information on its elements, its function and its pathologies. This analysis incorporates a quantitative characterisation method (scoring) to assess the state of corridors and tunnels. These methods are tested on infiltration and cracking pathologies for the risk analysis and on the notation of a corridor for the quantitative quantification.     

节能建筑的经济效益分析

给出了节能建筑的评价指标及计算方法,分析了节能建筑推广困难以及其经济评价研究难以深入的原因,并提出建议,以期推动建筑节能在我国的快速发展。     

A procedure for applying economic analysis to seismic design decisions

The seismic provisions of model building codes are often not enforced by municipalities because of an incorrect perception of the risks and benefits involved. The objective of this study is to present and evaluate a practical procedure which uses engineering and economic principles to optimize the design requirements for a single project. The procedure is applied to a six-storey building in St. Louis, Missouri. The example illustrates the relatively high levels of seismic resistance can be justified economically, even in areas of moderate seismic risk, such as St. Louis. Expansion of the procedure to code optimization is discussed.     

几种桩基的经济分析

本文根据福州地区某小区住宅的桩基选型所作的概算经济分析比较，通过计算机的计算，较准确地反映了各种桩基的经济指标。为设计方案的选择提供一个参考依据。通过本工程的实践建议基础造价作为设计桩型选择的一项指标。     

Quality vs risk: An investigation of their relationship in software development projects

Quality, risk and successful software development projects are three concepts which appear to be indisputably intertwined with one another. The purpose of the present study is to investigate the relationship between people quality, process quality and risk in the context of software development projects of Greek companies. Project team members with different characteristics were used as key respondents. The final sample consisted of 112 projects from 63 companies. Empirical data were analysed using the structural equation modelling technique. The main results indicate a negative effect of people quality on project risk level. On the contrary, process quality appears to have a slightly limited effect, defining only the risk level associated with the project team. The results contribute in the existing literature underlining the importance of quality on the reduction of the project risk level, thus, creating the necessary background for new similar research attempts in the future.     

集通铁路电气化改造工程可行性经济评价分析

对集通铁路电气化改造工程经济可行性进行分析,运用经济评价方法,进行投资估算和资金筹措策划,确定评价原则,并对运价、运量、投资和运营成本四项因素做敏感性分析,确定投资回收期、项目投资财务内部收益率,最终确定经济可行性,为类似工程进行可行性经济评价分析提供参考。     

浅析地勘财务风险

文章着重阐述地勘经济活动中,财务风险产生的内在原因及其具体的表现形式,并从微观角度对地勘单位的收益予以质化,从本质上提出防范风险、降低风险的各项措施,旨在将风险控制在可以承受的范围内.由此提高生产力,最大限度地增强市场竞争力.     

地铁车站安全风险分析

结合地铁车站工程实例,对地铁车站设计、施工中的风险识别与风险控制进行了分析和论述,介绍了地铁车站结构建设中常见风险点及其控制措施,以期减少地铁建设中安全事故的发生。     

建筑环境设计模拟分析软件DeST第10讲暖通空调方案的经济性分析

暖通空调方案的经济性评价是暖通空调设计过程中必不可少的环节,它必须针对暖通空调系统设计由浅入深、逐步深化的过程,在设计的不同阶段,尽可能准确地评价拟采用的暖通空调方案的经济性,从而为优化设计、比较方案提供经济方面的依据。详细阐述了DeST中暖通空调方案经济性分析所选用的模型与模拟方法。以一商用办公写字楼为例,针对暖通空调系统设计过程中的不同阶段,进行了方案的可行性分析和经济性分析,以此介绍经济性分析的方法和如何解决实际问题。     

Seismic risk analysis for reinforced concrete structures with both random and parallelepiped convex variables

This article develops an improved seismic risk assessment formulation exhibiting both random and bounded uncertainties using a probability and parallelepiped convex set mixed model. Limit thresholds for different types of components are described via a probabilistic model. The distribution parameters of limit thresholds are originally treated by employing a multidimensional parallelepiped convex model, in which marginal intervals are utilised to represent scattering levels for the distribution parameters, while relevant angle are employed to express the correlation between uncertain distribution parameters. The structural responses, i.e., engineering demand parameters (EDPs), are considered as correlated random variables and are assumed to follow a multidimensional lognormal distribution. A performance limit state function, which allows considering the relationship between the EDPs and the corresponding limit thresholds, is employed to reflect the coexistence of both random and parallelepiped convex variables. The limit state function is mapped into the standard parameter space via a transformation technique. Then, the improved seismic risk formulation, characterised through a probability and parallelepiped convex mixed variables, can be derived with the combination of the seismic fragility function and the ground motion hazard curve. The main purpose is to illustrate that the performance limit states should be properly modeled as random and parallelepiped convex mixed variables rather than only random or deterministic quantities. A six-story reinforced concrete building designed according to Chinese codes are used to illustrate the proposed approach for constructing hazard curves. The interstory drift and the peak floor acceleration are the selected EDPs, calculated through incremental dynamic analysis. The results demonstrate that the calculated failure probabilities for different limit states in 50?years are found capable of meeting the requirements of Chinese seismic norms after the proposed seismic risk formulation is adopted.     

蓄冰空调经济性分析软件的研制与应用

介绍了该软件的构成、功能和特点,该软件可完成空调负荷计算、蓄冰系统选择设计、全年能耗及运行费用计算、经济分析评估等任务。使用该软件对重庆某综合建筑的蓄冰空调系统方案进行了计算、并对计算结果进行了分析评估。     

A combined risk analysis approach for complex dam–levee systems

In many areas of the world, dams and levees are built to reduce the likelihood of flooding. However, if they fail, the result can be catastrophic flooding beyond what would happen if they did not exist. Therefore, understanding the risk reduced by the dam or levee, as well as any risk imposed by these flood defences is of high importance when determining the appropriate risk reduction investment strategy. This paper describes an approach for quantifying and analysing risk for complex dam–levee systems, and its application to a real case study. The basis behind such approach rely on the potential of event tree modelling to analyse risk from multiple combinations of ‘load-system response-consequence’ events, tested by the authors for a real case study. The combined approach shows how the contribution to system risk of each sub-system can be assessed. It also describes how decisions on risk mitigation measures, at the individual asset scale, can and should be informed in terms of how they impact the overall system risk.     

大开间灵活住宅工程的技术经济分析

本文通过大开间多层灵活住宅与全砖混小开间住宅在多方面的对比,运用大量的数据和表格,多角度多层次论证得出,大开间灵活住宅在建筑造价略高的情况下,能够提供住户更多的使用面积,使住户真正得到实惠;为住宅改造适应不同住户要求提供方便和可能;大开间底层布置商业,既可美化环境,又可方便生活.从长远看,其经济效益和社会效益更佳,技术经济效果明显,值得进一步推广.     

Reevaluation of health risk benchmark for sustainable water practice through risk analysis of rooftop-harvested rainwater

Health risk concerns associated with household use of rooftop-harvested rainwater (HRW) constitute one of the main impediments to exploit the benefits of rainwater harvesting in the United States. However, the benchmark based on the U.S. EPA acceptable annual infection risk level of ≤1 case per 10,000 persons per year (≤10⁻⁴ pppy) developed to aid drinking water regulations may be unnecessarily stringent for sustainable water practice. In this study, we challenge the current risk benchmark by quantifying the potential microbial risk associated with consumption of HRW-irrigated home produce and comparing it against the current risk benchmark. Microbial pathogen data for HRW and exposure rates reported in literature are applied to assess the potential microbial risk posed to household consumers of their homegrown produce. A Quantitative Microbial Risk Assessment (QMRA) model based on worst-case scenario (e.g. overhead irrigation, no pathogen inactivation) is applied to three crops that are most popular among home gardeners (lettuce, cucumbers, and tomatoes) and commonly consumed raw. The infection risks of household consumers attributed to consumption of these home produce vary with the type of produce. The lettuce presents the highest risk, which is followed by tomato and cucumber, respectively. Results show that the 95th percentile values of infection risk per intake event of home produce are one to three orders of magnitude (10⁻⁷ to 10⁻⁵) lower than U.S. EPA risk benchmark (≤10⁻⁴ pppy). However, annual infection risks under the same scenario (multiple intake events in a year) are very likely to exceed the risk benchmark by one order of magnitude in some cases. Estimated 95th percentile values of the annual risk are in the 10⁻⁴ to 10⁻³ pppy range, which are still lower than the 10⁻³ to 10⁻¹ pppy risk range of reclaimed water irrigated produce estimated in comparable studies. We further discuss the desirability of HRW for irrigating home produce based on the relative risk of HRW to reclaimed wastewater for irrigation of food crops. The appropriateness of the ≤10⁻⁴ pppy risk benchmark for assessing safety level of HRW-irrigated fresh produce is questioned by considering the assumptions made for the QMRA model. Consequently, the need of an updated approach to assess appropriateness of sustainable water practice for making guidelines and policies is proposed.     

挤扩支盘桩的施工与经济分析

结合具体的工程实例，阐述了挤扩支盘桩的施工工艺流程及优点，并对挤扩支盘桩技术进行了经济分析，实践证明，挤扩支盘桩技术效果良好，经济效益和社会效益显著。