地铁隧道盾构法下穿施工对地表既有铁路的变形影响研究

发布时间：2018-05-14 21:28

本文选题：盾构 + 地下穿越　；参考：《天津大学》2014年硕士论文

【摘要】：石家庄地铁一号线一期即将进入大规模兴建时期，隧道工程在施工过程中必然受到规划线路上各种复杂周边环境的制约，穿越各种高架桥、既有建筑物、构造物、管线等，在保证工程正常施工情况下，还要确保施工扰动对地表产生的各种影响在可控范围之内。本文以石家庄地铁1号线石家庄东站-东杜庄站盾构区间隧道下穿地表石德铁路为背景，对地铁盾构隧道施工对既有运营铁路的影响进行评估分析与研究。本文的主要研究内容包括：（1）分析介绍了盾构法隧道施工对地层的扰动机理以及地层沉降的主要特征，以石家庄地铁1号线实际地质条件为背景，利用有限元软件ANSYS14.0建立三维有限元模型，，分析预测盾构法施工对地表既有线路造成的沉降变形及水平变形影响；（2）根据施工条件，利用Ansys14.0有限元软件对双隧道施工工序进行优化，对比当两隧道的开挖面前后有间距时铁路的沉降差异，得到：当两隧道开挖前后间距大于24m时，铁路沉降与两隧道先后单独开挖时结果接近，地表铁路不再因隧道开挖顺序不同而产生附加的变形影响，为以后类似工程施工与设计提供参考。（3）建立弹性本构模型、弹塑性本构模型、以及弹性-弹塑性混合模型进行对比，分析了弹塑性模型与弹性模型在沉降计算中的差异性，并根据土体发生塑性变形的局域性建立弹性-弹塑性混合模型，对结构计算进行合理优化。（4）根据有限元子结构法原理，利用Ansys中超单元对弹塑性模型进行简化计算，在保证得到精确解的条件下，节省数值模拟计算所消耗的计算机时，为大规模工程模拟的合理简化提供参考。
[Abstract]:The first phase of Shijiazhuang Metro Line 1 is about to enter the period of large-scale construction. During the construction process of the tunnel project, it is bound to be restricted by various complicated surrounding environments on the planned lines, crossing all kinds of viaducts, existing buildings, structures, pipelines, etc. In order to ensure the normal construction of the project, but also to ensure that the construction disturbance on the surface of the various effects within a controllable range. Based on Shijiazhuang Metro Line 1 Shijiazhuang East Station-Dongduzhuang Station Shield tunneling under the ground surface Shide railway as the background of the subway shield tunnel construction on the existing operational railway impact analysis and research. The main research contents of this paper include: (1) analyzing and introducing the disturbance mechanism of shield tunneling construction and the main characteristics of stratum settlement, taking the actual geological conditions of Shijiazhuang Metro Line 1 as the background. The three-dimensional finite element model is established by using the finite element software ANSYS14.0, and the influence of shield construction on the settlement and horizontal deformation of the existing lines on the ground is analyzed and predicted. According to the construction conditions, the double tunnel construction procedure is optimized by using the Ansys14.0 finite element software. By comparing the difference of railway settlement between the two tunnels before and after excavation, it is concluded that when the distance between the two tunnels before and after excavation is more than 24m, the result of railway settlement is close to that of the two tunnels when they are excavated separately. The surface railway no longer has the additional deformation effect due to the different excavation sequence of the tunnel. It provides a reference for the construction and design of similar projects in the future. (3) the elastic constitutive model, the elastic-plastic constitutive model, and the elasto-elastoplastic mixed model are established and compared. The difference between elastic-plastic model and elastic model in settlement calculation is analyzed. According to the localization of plastic deformation of soil mass, the elastic-plastic mixed model is established, and the structure calculation is reasonably optimized. 4) according to the principle of finite element substructure method, Using the superelement in Ansys to simplify the elastic-plastic model can save the computer consumed by numerical simulation and provide a reference for the reasonable simplification of large-scale engineering simulation under the condition that the exact solution is obtained.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.43;U231.3

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