格拉管线适宜输油工艺流程方案的选择

以格拉管线为研究对象,深入探讨了成品油顺序输送管线可供选择的旁接罐流程为主及“泵到泵”密闭输送为辅的方案,减阻输送方案,“泵到泵”密闭输送为主及旁接罐流程为辅方案的可行性。通过对上述3种方案的分析对比,得出了选择“泵到泵”密闭输送为主及旁接罐流程为辅的输送方案为最适宜的结论,建议在技术改造中应用。     

广西河都高速公路顺高段隧道群设计方案比选

河都高速公路顺安至高岭段项目地形复杂、工程量艰巨,路线布设困难,如何选择最优的路线方案,是河都高速公路勘察设计要突破的重点和难点。文章结合工程概况拟定了两种路线方案,并从工程地质条件、工程规模、占地拆迁、营运效益和工程造价等方面对这两种方案进行比较,选出推荐使用的路线方案。     

A Quantitative Analysis of the Performance of Transportation Projects in Developing Countries

Abstract

This paper presents the results of a detailed quantitative analysis of performance metrics of a sample consisting of 89 transportation projects sponsored by the World Bank. The sample and a subset consisting of 65 projects were evaluated using the performance metrics of project cost, schedule and scope. The effect of project size (dollar value) and project duration on performance metrics was investigated. Also, the achievement of project goals and potential improvement in planning and estimating over time (the learning effect) was studied. It was found that, in general, in transportation projects sponsored by the World Bank, costs are overestimated and schedules are optimistic. The outcome with respect to cost seems counter‐intuitive because previous work by other researchers had shown a systematic underestimation of project costs. There is significant evidence that there are no efficient controls in place to predict or prevent schedule delays. The study also showed that during the past 15 years, no improvement (learning effect) was evident in project cost and duration estimation as the level of accuracy has not changed significantly. Further, it is observed that project duration did not affect the performance with respect to cost and delay.     

Cost escalations in the front-end of projects – empirical evidence from Norwegian road projects

This paper investigates an issue largely ignored in the transport literature on cost overruns, namely, cost increases in the early project phase, long before the decision to build is made. This is the phase of project planning that is referred to as the front-end phase in the literature. The rationale of the study is that unless cost estimates during the front-end phase are relatively accurate, the wrong projects may be selected for further development. We first argue for why it is important to address cost escalation during the front-end phase of project planning. We then use Norwegian data to demonstrate the magnitude of cost escalations during the front-end phase of projects and in comparison to the implementation phase. We find that even in a sample of projects with relatively small cost overruns as in the case of Norway, there are substantial cost increases before the formal decision to build was made. This raises the issue of whether decisions and priorities taken at the early stages of project development are based on false information and whether this may lead to the wrong project concepts being selected.     

公路基本建设项目设计阶段工程造价控制

公路工程造价控制,是工程项目管理的重要内容。文章分析了在公路基本建设项目设计阶段控制工程造价的重要性,阐述了设计阶段工程造价控制的必要条件,提出了对公路基本建设项目工程造价进行有效控制的措施。     

Greenhouse gas emissions from road construction: An assessment of alternative staging approaches

The greenhouse gas (GHG) emissions associated with road construction activities are analyzed. The main focus of this analysis is on the vehicle emissions associated with alternative project staging approaches, specifically a full closure of the road during construction, versus an intermittent road closure. The analysis includes the direct and upstream emissions associated with materials, construction equipment, mobilization of resources to the work site, and maintenance activity associated with the project over its lifetime. The analysis is based on one case study of a road project in New Jersey. The assumptions underlying the staging analysis are based on hypothetical approaches. Results provide an assessment of the main sources of project related emissions and the ability to minimize total project emissions by minimizing traffic disruption. In the analysis with a full closure of the road, traffic disruption accounts for 26% of total emissions, while with an intermittent road closure, traffic disruption accounts for only 2% of total emissions. The other main sources are from materials and life-cycle maintenance. The analysis demonstrates the feasibility of minimizing project related GHG emissions during road construction activities.     

Using longitudinal methods for analysis of a short-term transportation demonstration project

This paper documents an application of panel, or longitudinal data collection in the evaluation of a TSM (Transportation Systems Management) demonstration project. The project was a four-week demonstration of staggered work hours in downtown Honolulu during February–March 1988. The 4 wave panel survey elicited commuting experiences of approximately 2,000 downtown employees at two week intervals before and during the project. The sample involved both employees who participated in the project by shifting their work hours, and those who did not. The panel survey was augmented by floating-car observations of travel times on major routes into downtown Honolulu on the same four dates.The purpose of the analysis was to determine whether employee commute times were affected, and if so, how these changes were distributed among various employee segments. Two methods were used. First, travel time changes were estimated using paired t-tests. Second, regression equations were used to estimate project time savings as a function of trip length, route, and location of residence. Results show that travel time savings due to the project were typically small, less than ten percent. Nonparticipants experienced greater savings than participants, and some segments of participants experienced longer travel times during the project. The panel method proved to be an effective way to measure project travel time impacts and shows that the method is appropriate in short time applications.Presented at the Annual Meeting of Transportation Research Board, January 7–11. 1990, Washington, D.C.     

论公路工程档案质量管理

档案管理工作是一项基础性工作,建好工程档案对于进一步完善建设项目管理有着重要作用。文章结合新藤二级公路改建工程实例,对加强工程档案管理的方法与步骤进行了探讨,为公路工程档案管理工作提供参考。     

福州地铁施工围挡的分级分类设置研究

施工围挡是建设工程实行封闭施工的主要措施之一,施工围挡不仅体现一个城市品质,其安全和质量性能更涉及工程的顺利进行乃至人民群众的生命财产安全。本论文以福州地铁为例,根据施工所在区域的道路性质、周边环境、车站类型、施工工法、施工阶段及占道时长等因素,对施工围挡进行分级、分类设计研究,制定了不同阶段施工围挡的标准和技术参数,对今后类似工程工具有很好的借鉴意义。     

川藏铁路建设工程物流管理特征与体系

物流管理是川藏铁路建设工程的重要内容,与工程质量、工期、成本等目标密切相关。川藏铁路建设工程所需物资种类繁多,需求量大,运输及储备受到现场施工环境的制约,管理难度极大。因此,建立一套科学有效的川藏铁路物流管理体系对于铁路建设的精准实施具有重要保障作用。本文通过分析川藏铁路的物流特征,解析川藏铁路物流管理全要素,结合物流特征及研究方法构建了包含物资保障管理,物流运作管理,通道建设管理的川藏铁路建设物流管理体系。最后,针对川藏铁路物流管理中面临的矛盾与挑战,提出了相应的对策建议。     

航道疏浚工程施工浅点成因与控制分析

文章结合龙圩水道航道疏浚工程施工实例，着重从水下钻孔爆破作业方面，分析航道疏浚工程施工中出现浅点的主要原因，并提出相应的预防控制措施。     

关于江苏省高速公路绿色服务区后评估及管理制度的思考

本文根据江苏省不同区域的差异性,对已建高速公路运营期内的绿色服务区进行后评估,将项目实施过程及项目完成后的最终成果与项目决策时确定的各项目标进行全面系统的对比。通过系统地分析经济、社会、使用性、环境及经营管理等目标的影响程度,从中探索构建出高速公路绿色服务区项目后评估指标体系,并采用层次分析法为体系提供计算支持,最终对高速公路绿色服务区进行后评估研究,同时为保障绿色服务区的正常运营制定了相对应的管理制度。     

复合式路面加宽工程结构层拼接方案研究

复合式路面拓宽改建工程在国内尚属少数，其结构层的拼接技术尚缺少经验。文章结合工程实例，分析了复合式路面拓宽工程需解决的问题，探讨了复合式路面结构层拼接的优化方案，为类似工程提供参考。     

工程量清单计价模式下的合同管理研究

在招投标阶段，运用工程量清单计价办法确立的合同价款需要在施工过程中得到实施控制。而实现以项目为中心的施工合同协调管理，建立以合同管理为核心的项目管理体系，是提高项目管理水平的关键。文章基于施工合同管理中出现的风险分配和计价方式问题，提出工程量计价模式下的工程合同价款的约定事项、调整思路及效率优先的施工合同争议处理思路。     

正阳公路浅层软土地基处理的分析研究

通过对本路段浅层软基处治的多方案进行研究、探讨,试图寻找对于不同软土层厚度、不同埋深的浅层软土层的处治方案,以避免采用简单的土层置换方法,节约工程造价,减少工程投资。     

Mitigating environmental impacts in advance: Evidence of cost and time savings for transportation projects

The traditional model for mitigating a transportation project’s environmental impacts typically operates project-by-project and delivers the mitigation just-in-time. In contrast, the newer practice of advance mitigation comprehensively assesses and mitigates impacts from one or multiple transportation projects before or during project planning, sometimes long before project construction begins. The practice has gained adherents for its potential to improve ecological outcomes, by better aligning mitigation and conservation goals. Advance mitigation also stands to reduce mitigation costs, an important secondary benefit for transportation agencies with constrained resources. Evidence of cost savings, however, has been piecemeal and anecdotal. This paper advances knowledge of advance mitigation’s financial impacts in two ways. First, it critically assesses the evidence about cost savings realized through advance mitigation, both through avoided up-front costs and reduced project delay. Second, it directly estimates the project time savings that might accrue with advance mitigation of state highway projects in California. Overall, the balance of evidence is encouraging for transportation agencies that would introduce the practice, and general agreement exists on its financial benefits. Considering project delays related only to the environmental process, we estimate advance mitigation could reduce delivery times by 1.3–5.0 months per project. Still, we also identify factors limiting comprehensive analysis. Transportation agencies adopting advance mitigation practices into their operations could use a pilot approach that includes rigorous environmental and mitigation cost accounting; such pilots would build needed empirical evidence of advance mitigation’s financial and ecological outcomes.     

公路工程定额数据在线收集研究

随着我国公路建设事业的不断发展,定额管理部门对公路工程定额数据收集和处理的要求也越来越高。以河南省定额数据收集为例,分析公路工程定额数据收集的现状和存在问题,探讨定额数据在线收集的关键技术,提出B/S和C/S模式相结合的定额数据在线收集系统的体系结构,给出定额数据在线收集系统的网络构造方案。     

范家坪隧道喇叭口段施工技术

范家坪隧道为典型的由双线经喇叭口段过渡为两单线型式的大跨铁路隧道,为了提高施工效率、实现隧道两个掌子面同时掘进,施工中采用了喇叭口段由双线向单线反向施工方案,同时采取了可变式整体大模板液压台车台架配合小模板进行大跨段二次衬砌的施工技术。文章重点介绍了施工方案比选、施工步骤、施工效果。     

FMECA风险分析法在穿越管道施工过程的应用

外钓岛-册子岛水平定向钻穿越工程施工难度大,施工存在着很多风险。应用国际上先进的风险管理方法—FMECA定性风险评价法,对外钓岛-册子岛海底管道施工过程中的各类潜在事故进行了概率及后果影响评价,并据此采取了风险削减措施,为工程的顺利施工起到了很好的保障作用,同时也为国内外穿越工程施工安全及可靠性评价提出了一种新的方法。     

对城市轨道交通运营设施维修类项目招标工作的研究

城市轨道交通运营设施维修类项目是一项复杂的系统工程,其招标工作应当根据项目特点,有针对性地编制招标大纲,制订招标工作要点,使其在有关法律法规的约束下,公开、公平、公正地规范运作,达到社会效益与企业效益综合平衡的目的。