【作者】 崔奕；

【导师】 姜忻良；

【作者基本信息】 天津大学 ， 结构工程， 2008， 博士

【摘要】 地铁一号线是天津快速轨道规划线路中最重要的一条,它的建设将不仅大大完善天津市的城市基础设施,而且在促进城市合理布局、改善交通结构、保持生态环境等方面具有重要的经济和政治意义。本文围绕天津地铁一号线土建工程中的几个关键技术问题,分别对盾构掘进对地面隆起及沉降的影响、SMW工法在基坑工程中的应用、地铁双层车站地下隧道交叉相互影响的抗震研究等几个问题进行了分析研究,并用部分实测数据对分析结果进行了验证,得出了一些有价值的结论,为天津地铁一号线的设计和施工积累了经验,同时也为其它的地铁建设提供参考。本文的主要工作如下:(1)通过对小白楼至下瓦房区间盾构施工段进行现场实测,给出了地面及地层隆起与沉降曲线、不同深度地层侧移曲线,分析总结了泥土加压式盾构施工过程中周围土体的变形规律;本文还利用有限元软件建立三维有限元模型,对盾构隧道开挖过程进行了动态模拟。通过与现场实测数据对比分析表明,有限元计算结果与实测结果吻合良好,模型能较好地反映工程实际,为天津今后的地铁工程建设提供理论依据。(2)通过对洪湖里站3号出入口基坑支护工程进行的钢轨一水泥土组合墙施工试验、组合墙抗弯试验、组合墙水平侧移和地面沉陷监测试验以及钢轨的拔出试验,研究了在天津特有的地质条件下,用废旧的钢轨代替大规格H型钢的SMW工法施工中的水灰比确定问题、钢轨在水泥土挡墙中的效用发挥问题、基坑开挖对钢轨-水泥土组合墙水平位移以及地面沉陷的影响问题、钢轨的回收问题等,为今后工程的设计和施工提供参考。本文还对该基坑支护工程进行了有限元模拟,通过和试验数据的对比分析,验明了计算程序和所选取参数的正确性。(3)由于地下结构的抗震分析远不如地面结构成熟,很有必要对地铁结构,尤其是地铁隧道交叉处进行抗震分析。本文采用有限元法,分析了天津地质条件下交叉隧道的地震反应,研究其上层车站和下层车站地震作用下的位移和层间位移、层间剪力的变化规律;本文还对成层地质条件下、不同埋深、不同软弱层深度条件下的地铁隧道进行抗震分析,揭示了不同地质条件下交叉隧道的地震反应规律,为地铁车站的设计提供指导性意见。更多还原

【Abstract】 Tianjin Subway No.1 Line is the most important line in the plan of Tianjin express rail transit system, the construction of which will not only perfect the municipal infrastructure of Tianjin, but also play an important role both economically and politically in promotion of reasonable urban layout, improvement of communications structure and maintaining sound biological environment. This dissertation covers analysis and research on several key technical problems involved in the civil engineering of Tianjin Subway No.1 Line, including influences of shield tunneling on ground surface upheaval and subsidence, applications of SMW construction method in construction of foundation pits, earthquake resistance and mutual influences of double-deck subway station crossed underground tunnels, etc. The analysis results are verified by measured data and several valuable conclusions have been obtained, allowing an accumulation of experience for design and construction of Tianjin Subway No.1 Line, and at the same time, a reference available for other subway projects. The dissertation mainly focuses on the following aspects:(1) Based on the on-site measurements on the shield tunneling section from Xiaobailou to Xiawafang, ground surface and stratum upheaval and subsidence curves, lateral displacement curves of stratums at different depth are presented; deformation rules of surrounding soils during shield tunneling with pressure on soils are analyzed and summarized; this dissertation also includes 3D finite element modeling established by finite element software to make dynamic simulation of shielding tunneling. Comparisons with data from on-site measurements and analysis show that results from finite element calculations are in good agreement with data from the actual measurement, and it shows that the modeling can fairly reflect practices in construction, which provides a theoretical basis for future subway construction in Tianjin.(2) Several problems in the special geological conditions in Tianjin are studied based on various tests in construction of foundation pit supports at No. 3 gateway of the Honghuli station. Such problems studied include ratio between water and cement in the SMW construction method that uses secondhand steel rails to replace large specification H profiles, roles of steel rails in cement-soil retaining walls, influences of foundation pit excavation on horizontal displacement of the steel rail-cement soil combination walls and ground surface subsidence and recovery of steel rails; and the tests made in the construction include construction of rail-cement soil combination walls, bending-resistance of the combination walls, horizontal displacement of the combination walls, ground surface subsidence and steel rail pull-out, etc. All the tests and studies have provided references to the future engineering designs and constructions. The dissertation also includes finite element simulation of the foundation pit supports, and it is compared with the test data. The comparison and analysis prove correctness of the calculation program and parameters selected.(3) As underground structure earthquake-resistant analysis is much less mature than that of the ground structures, it is absolutely necessary to make earthquake-resistant analysis for the subway structure, especially crossings of subway tunnels. In this dissertation finite element method is used in analysis on seismic reactions of crossed subway tunnels in the Tianjin geological conditions, in studies on changing rules of displacement, inter-layer displacement and inter-layer stresses of the upper and lower deck of subway stations under earthquakes. Besides, this dissertation also includes earthquake-resistant analysis on subways under stratified geological conditions at different depth underground and different weak stratums, which reveals seismic response rules of crossed subway tunnels in different geological conditions, providing instructive opinions for designers of subway stations.更多还原