通—胡区间隧道暗挖施工对既有桥梁桩基础的变形影响规律

发布时间：2018-01-12 06:14

本文关键词：通—胡区间隧道暗挖施工对既有桥梁桩基础的变形影响规律　出处：《西安科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：开展西安黄土地区地铁区间隧道浅埋暗挖施工对既有桥梁基础的变形影响规律研究具有重要的理论意义和工程参考价值。本文以西安地铁三号线通化门~胡家庙区间隧道浅埋暗挖施工为依托工程，采用理论分析、数值模拟和现场监测相结合的方法开展论文的研究工作，并提出相应的变形控制技术。主要工作和结论有：（1）从理论方面分析了地层特性、地下水、隧道埋深、施工工法和开挖进尺等因素对地表变形的影响规律和浅埋暗挖施工引起的地层变形特征。研究表明，邻近桩基础的埋深越大，浅埋暗挖隧道施工越容易引起基础发生倾斜，同时浅埋暗挖隧道施工诱发的地层变形主要通过水平变形和竖向变形两方面影响邻近的桥梁桩基础产生不同形式的变形。总结归纳了隧道暗挖施工中常用的地表和桥梁桩基础的变形控制措施，同时结合西安地区施工经验，提出了通—胡区间隧道暗挖施工诱发的地表和桥梁基础的变形控制标准。（2）采用FLAC3D软件，研究通—胡区间隧道暗挖施工对既有桥梁桩基础的变形影响规律。对比分析台阶法和CRD法两种暗挖施工方法诱发的地表和东二环长乐桥的变形规律，模拟结果表明，相比于台阶法施工，CRD法施工诱发地表和长乐桥产生的变形均比较小，但施工中还是需要对桥梁提出变形控制措施。通过暗挖施工方案的比选，且考虑到饱和黄土地层施工降水困难问题，应采用对桥梁桩基础变形影响较小的CRD工法进行湿陷性黄土地层的隧道施工。（3）为控制CRD法施工所引起地表和既有桥梁基础的变形，采用袖阀管注浆加固技术加固桥梁桩基础周围的地层土。结合实际工程，制定施工现场变形监测方案，对比分析现场监测结果和预测结果。研究表明，实测的地表沉降曲线和模拟预测的变形趋势基本一样，采用袖阀管注浆加固措施后，地表和长乐桥的变形控制在允许范围内，确保了暗挖隧道施工期间桥梁的安全运营。
[Abstract]:It is of great theoretical significance and engineering reference value to study the influence of shallow tunneling construction on the deformation of existing bridge foundation in Xi'an Loess region. This paper uses Tonghua Gate ~ Hujiamiao of Xi'an Metro Line 3 as a reference. The construction of shallow burying and digging in interval tunnel is based on the project. Theoretical analysis, numerical simulation and field monitoring are used to carry out the research work in this paper, and the corresponding deformation control techniques are put forward. The main work and conclusions are as follows: 1) the influence of ground characteristics, groundwater, tunnel depth, construction method and excavation rule on surface deformation and formation deformation characteristics caused by shallow underground excavation are analyzed theoretically. The larger the buried depth of the adjacent pile foundation, the more prone to the slope of the foundation caused by the shallow excavation tunnel construction. At the same time, the formation deformation induced by shallow excavation tunnel mainly affects the adjacent bridge pile foundation through horizontal deformation and vertical deformation. The paper summarizes and summarizes the ground surface commonly used in tunneling construction. And the deformation control measures of bridge pile foundation. Combined with the construction experience in Xi'an area, the deformation control standard of ground surface and bridge foundation induced by tunneling construction in Tonghu region is put forward. FLAC3D software is used. The influence of tunneling construction on the deformation of existing bridge pile foundation is studied, and the deformation law of surface and east second ring Changle bridge induced by step method and CRD method are compared and analyzed. The simulation results show that the deformation induced by the CRD method is smaller than that of the step method. However, it is still necessary to put forward deformation control measures for the bridge during construction. Through the comparison and selection of the construction scheme of the underground excavation, and considering the difficult problem of the construction of saturated loess layer, the problem of dewatering is also taken into account. The CRD method, which has little influence on the deformation of bridge pile foundation, should be used for tunnel construction of collapsible loess stratum. In order to control the deformation of the ground surface and the existing bridge foundation caused by the CRD method, the soil layer around the bridge pile foundation is strengthened with sleeve valve pipe grouting. The results of field monitoring and prediction are compared and analyzed. The results show that the measured surface settlement curve is basically the same as the simulated deformation prediction. The deformation of the ground surface and the Changle bridge is controlled within the allowable range after the sleeve valve pipe grouting is adopted to ensure the safe operation of the bridge during the construction of the underground excavation tunnel.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U443.15;U456.3

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