岩溶隧道施工全过程风险管控措施

岩溶隧道是高速公路建设工程中的难点.岩溶地质灾害严重影响隧道施工工期、施工质量,并极大地增加了施工安全风险.文章提出了岩溶隧道施工全过程风险管控的理念,并针对当前隧道施工安全管理存在的一些问题与不足,结合实际工程案例,从施工前、施工中、施工后三个阶段对岩溶隧道风险管控措施进行了探讨,以期为同类工程提供参考.     

高速公路隧道施工风险管理措施探究

高速公路隧道施工中,需重视提升施工风险的管理能力,明确高速公路施工风险的特点及原因,掌握高速公路隧道施工风险辨识方法,进行高速公路隧道施工安全风险的科学评价,识别高速公路隧道施工常见的风险,落实有效管理措施,对涌水风险、坍塌风险、有毒有害气体风险进行全面深入的管理控制,保障高速公路隧道施工安全、可靠的开展,掌握风险管理的主动权.     

大断面公路隧道紧急停车带施工方案比选

考虑到安全运营需要,目前我国高速公路特长隧道均设置了紧急停车带。紧急停车带施工难度较大,安全风险较高。结合山西高速公路花石崖隧道紧急停车带施工工程,通过三个施工方案的比选、论证,确定了在本隧道地质围岩等条件下,采用三台阶七步法开挖,并介绍了方案实施情况,期望能为同类隧道紧急停车带施工提供借鉴。     

基于云计算的隧道施工安全风险控制系统研究

文章介绍了云计算技术的概念和应用范围,全面总结了隧道施工的风险因素,完成了基于云计算的隧道施工安全风险控制系统的设计,并以河池2#隧道施工为例,对该隧道的施工风险概率进行评估,论证了该风险控制系统设计的正确性。     

兰渝铁路熊洞湾隧道煤矿采空区施工安全控制技术

新建兰渝铁路熊洞湾隧道属极高风险隧道,隧道穿越软弱破碎煤系地层,围岩内富存采空区,主要存在煤窑采空区及瓦斯问题,属典型煤系地层隧道.文章首先针对该隧道穿越采空区施工过程中面临的各种风险(包括采空区施工风险、瓦斯突出风险、突泥与突水风险、围岩大变形风险及塌方风险等)进行了综合分析;进而从施工监理角度有针对性地提出了风险规避措施,包括重大危险源方案审查、综合超前地质预报技术、施工资源控制,以及对施工单位施工过程的管理、行为控制等.     

盾构隧道施工风险知识管理系统的设计开发

介绍适用于盾构隧道施工期风险的管理流程,并构建出一套盾构隧道施工风险评价体系和盾构隧道施工风险知识管理系统的新概念。该系统可促进施工企业知识资源的优化配置,同时通过对工程施工期风险进行有效管理,有利于施工企业对施工成本、工程进度、工程质量和环境安全的全面控制。     

公路隧道新奥法施工全过程风险管理分析

为减少影响公路隧道新奥法施工质量的因素,强化新奥法的使用效果,弱化风险事故产生的概率,介绍新奥法施工全过程中的风险因子,结合广东汕湛高速某标段隧道,开展风险评价及控制分析,以便为隧道施工提供理论参考。     

嘉华隧道施工安全风险控制应用

结合重庆嘉华工程嘉华隧道施工,从安全风险控制出发,分析了城市公路隧道施工的危险源,采取了适当的安全风险监测手段,通过对安全风险源的监测.及时发现安全发展趋势,及时提出了修改完善施工工艺和施工参数建议,使嘉华隧道施工安全风险得到有效的控制.同时通过对施工资料和过程中的监测数据资料分析研究,使隧道施工安全和进度得到最优结合.     

基于AHP层次分析法的湿陷性黄土隧道洞口施工风险管理研究

为科学地评估湿陷性黄土隧道洞口开挖时的施工风险因素,本文以定临高速紫云山隧道为例进行了风险研究。考虑到紫云山隧道上覆岩层破碎,广泛分布湿陷性黄土,极大地增加了隧道洞口段施工的评价指标体系的复杂性,采用AHP法对各类因素的权重予以确定。基于建立的风险指标评价体系,采用BP神经网络对隧道风险等级进行评价。进而获得了紫云山隧道施工中存在的风险因素权重,明确了湿陷性黄土隧道洞口段开挖风险管理的关键环节,针对这些关键环节制定出相关的管理方法和技术措施,为后续的项目施工管理指明方向。     

隧道施工风险评估关键技术研究

施工技术、施工环境以及施工设备是隧道施工中的主要安全风险因素。文章立足于上述风险因素,从梯阶层级搭建、风险因素的权重核算及层级因素排序等方面,研究了隧道施工的安全风险评估关键技术,并结合工程案例,验证所研究的技术是否满足隧道施工安全风险评估要求。     

Survey of R&D in PRT systems

A survey of research and development in advanced transit has been made by Chalmers University of Technology in Gothenburg in cooperation with Trans21 in Boston. Summary findings are reported for fourteen academic research programs and ten development programs for PRT. An earlier version of this paper was presented at the International Conference of PRT and other Emerging Systems held in Minneapolis in 1996.     

The Impact of Container Type Diversification on Regional British Port Development Strategies

Abstract

Despite a concentration of container traffic in the southeast of the UK over the last few decades, regional ports are attempting new development strategies to capture or retain specific traffic segments. These include intra-European short-sea traffic and a potentially increasing feeder market. These trends are reflected in the movement of different container types, which result in a number of planning challenges related to changing infrastructural and operational requirements. This paper uses highly disaggregated data on container type movements to address three issues that can inform these planning challenges. First, the imbalance of trade resulting in empty container repositioning; second, the requirement for gauge-cleared rail routes to cater for the increasing proportion of high-cube containers; and third, the specialisation of European short-sea traffic at secondary UK ports. The results reveal the disproportionate repositioning of empty containers at Scottish ports and the importance of 45?ft, high-cube and pallet-wide containers at regional ports, highlighting their focus on intra-European short-sea traffic and raising difficulties relating to their lower quality of landside infrastructure (particularly rail) in comparison to the large south-eastern ports. The potential repercussions on hinterland infrastructure development raise questions about both public and private sector responses to regional port development.     

管道风险分析指数评分法中分值调整初探

管道风险分析指数评分法中重要步骤之一就是确定影响管道事故因素的权重,各个管道风险因素在整个管道事故中所占的权重是不相同的。针对目前管道风险分析指数评分法基本假设之一（各因素的分值范围都是0～100分）,为了更加客观、准确、合理地反映各个风险因素对于管道事故的影响程度,提出并论述了依据层次分析法的数学逻辑性进行综合计算得出管道风险因素的权重,然后对评分法中各个因素的最高分值,根据其权重不同进行相应调整,从而增强评价者对风险因素的认识和评判能力,提高管道风险评价结果的准确性。     

A century of evolution of the accessibility concept

The concept of accessibility has acquired numerous meanings along multiple dimensions during the century of its evolution. This essay argues for the salience of two dimensions: application-based and definition-based. In its application, accessibility has incorporated positive and normative dimensions which have varied in prominence over time. In its definition, accessibility has varied between a mode of evaluation incorporating measured mobility and proximity, on the one hand, and a predefined market basket of urbanist improvements to transportation and land use systems, on the other. Advocates of the accessibility shift should emphasize both the measured approach to accessibility and accessibility’s normative side.     

天然气站往复式压缩机活塞失效分析

针对天然气站往复式压缩机活塞的断裂事故,运用失效分析方法,开展了活塞断口扫描电镜分析、能谱和金相分析。根据断口形貌的电镜和金相观察结果,结合理论知识,分析确定了该活塞发生断裂事故的主要原因,即在特定工况下该活塞的材料缺陷是造成断裂的主要因素。     

中国城市道路规划方位性问题研究

文章结合中国的传统建筑文化理念和现代科学原理,从历史文化、能源节约、环境保护、房地产定价、交通安全等多方面分析研究了城市道路在规划和设计时所应遵从的定向规则。     

Planning guidelines for metro–bus interchanges by means of a pedestrian microsimulation model

The big paradigm for cities nowadays is to study the movement of pedestrians at the interface between metro and bus systems – metro–bus interchanges. When these interchanges are not well designed, walking is inefficient and can be unsafe for pedestrians. This paper analyses, by means of a pedestrian microsimulation model, metro–bus interchange spaces in order to propose planning guidelines for the city of Santiago de Chile. Specific objectives are (1) to identify the variables that provide efficiency and safety in those spaces; (2) to simulate different scenarios using the pedestrian simulation model LEGION; (3) to propose planning and design guidelines for pedestrian spaces at metro–bus interchanges; and (4) to contrast the recommendations in the recently opened terminal station on Line 1 of Metro de Santiago: Los Dominicos Station.     

Predicting queue variability to enable analysis of overload risk

ABSTRACT

Predicting the risk of traffic demands and delays exceeding critical limits at road junctions, airports, hospitals, etc., requires knowing how both mean and variance of queue size vary over time. Microscopic simulation can explore variability but is computationally demanding and gives only sample results. A computationally efficient approximation to the mean is used in many modelling tools, but only empirical extensions for variance in particular situations have been available. The paper derives theoretical formulae for time-dependent and equilibrium variance, believed to be novel and to apply generally to queues covered by the Pollaczek–Khinchin mean formula, and offering possible structural insights. These are applied in an extended approximation giving mutually consistent mean and variance estimates with improved accuracy. Tests on oversaturated peak demand cases are compared with Markov probabilistic simulation, demonstrating accuracy (R^2?>?0.99) for typical random, priority-like (M/M/1) and traffic-signal-like (M/D/1) queues. Implications for risk analysis, planning and policy are considered.     

生命大过天

文章介绍了广西壮族自治区公路管理局开展专项行动,治理以桥梁为重点的交通基础设施安全隐患的情况,针对在役桥梁、在建桥梁和农村公路桥梁存在的安全隐患提出了相应的治理措施。