公路隧道下穿已运营铁路隧道施工及安全监控

文章主要介绍了福建省龙(岩)-长(汀)高速公路隘岭隧道下穿赣(州)-龙(岩)铁路古城隧道的施工工艺和施工方法,并简要阐述了对施工中的公路隧道和运营中的铁路隧道所采取的安全监测措施。     

水库蓄水后对既有傍山铁路隧道运营安全的影响研究

针对水库蓄水后将对既有傍山铁路隧道的运营安全产生影响的问题,文章通过数值方法,分析了横江干流盐津-杨柳滩五级水库对内昆铁路水(富)-盐(津)段麻石山隧道安全性的影响,对比了水库蓄水前后隧道二次衬砌内力、安全系数的变化规律,给出了隧道结构需要加固或防护的依据,对今后的水库建设有指导作用.     

秦岭Ⅲ号隧道破碎围岩涌水段施工技术

破碎围岩一直是隧道施工所面临的难点，而破碎围岩地段出现大量涌水更是给隧道安全掘进增添了难度，本文以西(安)-汉(中)高速公路秦岭Ⅲ号隧道为例，介绍在隧道破碎围岩涌水段采用深孔超前排水结合超前小导管双液注浆堵水综合防治施工技术，确保隧道安全掘进的实践案例，为今后同类工程施工提供借鉴。     

襄阳汉江沉管隧道设计关键技术北大核心CSCD

基于襄阳汉江沉管隧道的工程设计实践,针对该隧道强冲刷、强透水地层深厚、防洪要求高等特点,对隧道平纵布置、管节及接头止水结构、干坞选型及结构、沉管基础及回填、沉管最终接头及对接端止水结构等进行了研究。结果表明:(1)内河沉管隧道采用长距离双轴线干坞布置方式,通过格形地下连续墙、超深落底式帷幕、地下连续墙预应力锚索垂直支护和混凝土封底组合技术解决了强透水地层深基坑支护及隔水难题;(2)采用全断面顺浇技术进行整体式管节预制,实现了管节接头止水设施的全国产化;(3)在内河沉管隧道采用高精度浮式整平先铺卵石基础,并提出了强冲刷区管顶防冲保护解决方案;(4)采用了不设独立止推构造的陆域最终接头,并针对工程需求设置了大直径锁口钢管桩配合外侧止水墙的对接端支护结构及分片整体吊装双壁钢围堰二次止水结构。     

水压致裂地应力测试法在茅坪隧道中的应用与研究

高地应力以及由此诱发的地质灾害(如岩爆等)是目前隧道施工中经常遇到的工程地质问题,地应力测试则是进行隧道岩爆及其他灾害预测预报的重要内容.本文通过对福建省闽北地区公路隧道-茅坪隧道钻孔XS10的水压致裂地应力测试成果的分析研究,对测试区域的地应力水平及隧道围岩稳定性做出了评价,从而为该地区隧道的地应力参数及岩爆分析评价...     

以消防性能化设计思路优化双线隧道间人行横通道的设置

双线隧道间人行横通道的设置一直是隧道工程建设中的重点和难点。通过介绍美国NFPA502标准以及《道路隧道设计规范》(DG/TJ 08-2033)中对隧道人行横通道/应急出口设置,分析和总结了国内外已建隧道工程中人行横通道的设置方法,提出了人行横通道的设置应采用"处方式"和"性能化"设计相结合的方法。     

浅埋大断面黄土隧道下穿高速公路设计方案研究

结合郑州至西安客运专线阌乡隧道科研试验段测试结果,对大断面黄土隧道(175 m2)、浅埋(10 m)、斜交(15°)、长距离(270 m)下穿连-霍高速公路设计方案进行了研究,制定了双层大管棚超前支护、双层初期支护及双侧壁导洞法施工的下穿方案.施工实践表明,本工程的设计是成功的,特别是设置双层大管棚效果明显,有效地保证了施工安全,使连-霍高速公路路面沉降控制在5cm以内.     

借助既有结构进行天桥吊装对邻近建（构）筑物影响分析

上海金沙江路真北路人行天桥结构分块吊装需设置较多临时支撑及桩基,桩基距离既有地道、车站及区间隧道距离较近。在中环金沙江路地道光过渡段中隔墙上设置临时支撑,借助既有建（构）筑物结构进行吊装施工。对此施工方案进行了数值模拟和分析,以评估其对邻近既有地下建（构）筑物的影响程度。     

基于多变量GP-DE模型的隧道变形时间序列预测研究

准确预测和控制隧道变形是确保隧道工程施工安全的重点。针对目前隧道围岩变形时间序列预测的不足,文章提出了一种基于多变量高斯过程(GP)-差异进化算法(DE)的隧道变形时间序列预测方法。根据隧道自动化监测结果进行多变量相空间重构,并通过主成分分析法降低输入维数。在此基础上采用GP-DE模型进行隧道变形预测研究。以吉林省高丽沟隧道围岩拱顶位移为例进行预测,将预测结果与BP神经网络、SVM模型预测结果进行比较。研究结果表明,多变量时间序列的GP-DE模型具有更高的预测精度,预测值与实测值吻合更好,是一种有效的隧道位移预测方法。     

水底隧道衬砌背后水荷载作用形式及大小研究

随着我国水底隧道的修建,地下水的作用形式及衬砌背后水荷载大小的确定已亟需解决。文章以某水底隧道为工程背景,采用有限差分软件FLAC3D对水-土(岩)分算、水-土(岩)合算、流固耦合地下水封堵、自由排水等四种工况进行分析研究,通过四种工况数值计算结果的比较,得出了一些有价值的结论,可以为设计者提供参考,以优化水底隧道的设计。     

Analysis of factors affecting the choice of route of pedestrians

Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD).

An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip.

It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links.     

Non-parametric analyses of efficiency of airports

This paper estimates the efficiencies and productivity changes of 12 international airports in the Asia-Pacific region based on data from 1998 to 2006. We apply stochastic frontier analysis (SFA) to compute efficiency estimates and use the Malmquist productivity index (MPI) to analyze productivity changes. We use the SFA model with a translog-type production function after testing the statistical hypotheses. According to the results of the SFA hypothesis tests, airports have experienced a technological regression; the deviations from the efficiency frontier are caused more by technical inefficiency than random noise. However, the inefficiency was found to decrease. The MPI reveals a declining trend resulting more from technological change than from efficiency change, with a decrease in inefficiency. Taken together, both the hypothesis tests and the MPI not only provide consistent conclusions, but also suggest that airports should concentrate on technological progress.     

波纹管应力分析研究进展

评述了波纹管应力理论研究方法的进展情况，围绕解析法、工程近似法和数值法，对波纹管理论研究中的一些主要成果作了较详细的回顾和总结，对各种研究方法作出了评价，展望了亟待解决的一些问题。     

实现多组态计量软件集中监控的可行性分析

天然气自动计量系统有多种组态软件,由于软件的不相通性,造成了计量系统数据采集的通用性差、数据传输与入库的时效性差、数据利用的可靠性低.结合各组态软件的实际情况,从设计上充分利用Oracle大数据处理能力以及Partition(分区表)的特性,实现历史数据的存储,应用WebService与COM+数据访问组件提供多层数据访问架构,采用OPC与DDE工业数据交换协议,实现了各站场计量数据的实时上传,为连续数据采集和实时监控提供了可能,节约了改造成本.     

注汽管道承压能力评估和实物试验验证

基于失效评估图技术对某注汽管道进行了承压能力评价,给出了管线在不同腐蚀壁厚情况下的极限承压能力和极限裂纹尺寸。并利用实物爆破试验验证了评价方法的安全性和有效性,通过对爆破断口进行宏观和微观分析,发现管段的开裂属于脆性开裂。     

输油管道中原油乳状液的流变性研究

原油乳状液的流变性是原油开采后在管道中输送的重要研究方面,为了更好地研究这一性质,采用电动搅拌机、偏光显微镜以及流变仪等仪器来测定不同含水率的原油乳状液在不同条件下的黏度,观测不同含水率的原油乳状液在偏光显微镜下的形态。并且分别对原油乳状液的黏度与含水率之间的关系以及与剪切速率之间的关系进行研究,初步确定了所测区块原油乳状液的转相点以及该区块原油乳状液的流变特性,为生产中的油气集输提供了理论依据。     

埋地管道防腐保温层失效评价

明确埋地管道防腐保温层的技术评价标准,对埋地钢质管道的安全运行,延长管道使用寿命具有重要意义。为了对埋地管道防腐保温层做出有效评价,从间接检测与开挖检测2个方面,结合现场检测数据,提出了基于防腐保温层的电流衰减率、绝缘电阻率、质量状况与厚度的分级评价标准及基于4种评价指标的综合评判方法。工程实践表明,该评价标准对防腐保温层是否存在失效能做出有效判断。     

城市轨道交通杂散电流监测系统概述

介绍了城市轨道交通工程中杂散电流不同的监测系统的构成,分析了集中式、分散式和智能型等监测系统的配置和功能,以及智能型实时在线监测系统的重要意义,为轨道交通工程杂散电流监测系统的选择与应用提供参考。     

Preliminary results of an analysis of areas of influence in Shanghai

The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda.     

Direct analysis of the perceived importance of attributes of reliability of travel modes in urban travel

Reliability of travel modes was found to be the most important characteristic of transportation systems in several attitudinal investigations of individual travel behavior. This paper represents the first part of a research effort aimed at gaining a better understanding of the characteristics of reliability of transportation modes in urban travel. In this research, reliability characteristics are identified; their importance relative to each other is assessed, and an insight into possible structure of an objective reliability index is discussed. The research is based on perceived values of reliability, which were identified through a large attitudinal survey conducted in the Chicago metropolitan area.