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大断面矩形顶管隧道施工在城市地下空间施工中得到广泛应用,但其衬砌结构病害日益突出。为了防治大断面矩形顶管隧道衬砌结构病害,分析隧道大断面矩形顶管施工风险,探讨大断面矩形隧道沉降、姿态控制重难点,阐述隧道衬砌混凝土施工常见病害的分类及成因,提出隧道衬砌混凝土施工病害的防治措施,讨论大断面矩形隧道顶管顶进施工技术发展趋势,为实际工程应用提供理论和技术指导。 相似文献
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西峡隧道采用全液压大模板衬砌台车、泵送混凝土进行二次衬砌施工.但由于单线隧道净空狭小,为保证开挖运输,便给衬砌台车的加工及稳定性控制增加了一系列难度.由于对台车的主要尺寸及刚度进行了检算,并摸索出一些经验,采取了一些有效措施,才使二次衬砌施工得以顺利进行. 相似文献
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隧道火灾对人员生命产生威胁的同时也会对隧道结构安全产生影响.首先,根据火灾时的实际情况建立了地铁区间隧道火灾烟气三维温度场.其次,考虑隧道壁面与高温烟气的热对流、热传导、衬砌材料传热性能的非线性以及衬砌混凝土爆裂建立了火灾时衬砌温度场求解的基本方程与求解方法,对比试验结果验证了所提方法的准确性.再次,结合求解得到的三维... 相似文献
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碳纤维布在连拱隧道衬砌裂缝病害治理中的应用 总被引:1,自引:0,他引:1
延安至安塞高速公路墩山连拱隧道主体工程完工后,衬砌出现了不同程度的裂缝和渗漏水等病害,通过对衬砌裂缝特征、产生原因的分析,并根据裂缝的开裂程度与发展规律,采用碳纤维布对隧道衬砌裂缝进行了局部修复和整体加固补强。由于在施工过程中严格控制施工工艺和施工质量,达到了预期效果。通过碳纤维加固模拟和监测表明:衬砌裂缝得到了有效控制,支护受力处于安全状态,围岩稳定,碳纤维布加固效果显著。 相似文献
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高速公路运营隧道火灾损伤后,若衬砌结构出现表层起层剥落的严重损伤区,会危及隧道结构安全而使高速公路暂停运营。为避免该情况发生,以沙厦高速公路泉州德化段龙岭隧道火灾损伤抢修治理工程为例,对该隧道火灾后的损伤区进行检测及评估,采用镀锌钢板和化学锚栓相结合的方法对该隧道进行加固,加固后隧道未出现明显的应力应变波动和衬砌表观病害,加固效果良好,确保了隧道的正常运营。 相似文献
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为提高高速公路隧道衬砌病害预防与治理效果,对高速公路隧道衬砌病害类型、成因与治理措施等进行分析。隧道衬砌病害类型主要包括裂缝、渗漏、剥落、变形、腐蚀和冻融破坏等,其成因主要包括混凝土质量问题、施工工艺不当、环境因素、设计问题和运营管理问题等。基于此,提出优化混凝土配合比、改进施工工艺、采用先进防水技术、加强隧道衬砌的监测与维护、采用高性能混凝土和加强隧道设计优化等措施,以期为高速公路隧道衬砌施工与病害治理提供参考。 相似文献
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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. 相似文献
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《Transportation Research Part A: General》1991,25(6):407-418
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. 相似文献
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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。 相似文献
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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。 相似文献
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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. 相似文献
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Joseph N. Prashker 《Transportation》1979,8(4):329-346
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. 相似文献
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