桩墙支护基坑开挖引起的土体变形计算方法研究
发布时间：2019-03-20 14:51
【摘要】：随着城市高层建筑和地下市政工程的不断发展,基坑工程施工周边环境也越之复杂,这就要求对基坑施工引起的周围土体的变形进行控制。因此,如何准确预测地层的变形成为基坑工程设计计算中一个越来越重要的问题。目前,对基坑开挖引起的地层变形的研究多集中在预测基坑周围地表沉降,很少涉及地表以下土体的变形,且多为经验、半经验方法,缺乏必要的理论依据,计算结果存在较大的误差。针对这一问题,本文提出一个基于Melan位移解的基坑开挖引起的地层变形的计算方法。本文的主要研究内容及成果如下:(1)运用弹性力学中平衡方程、应力几何方程对Melan应力解正确性进行验证,发现其错误并进行更正,然后推导出其相应的位移解。(2)研究了由不同方法得到的位移解公式,分析了造成差异的原因。针对基坑开挖时的变形特点,提出将Melan位移解用于基坑开挖问题的修正办法。(3)通过对Melan位移解进行积分,得到单元均布荷载作用下的位移解,用以模拟基坑开挖时使土体产生变形的作用荷载。(4)将基坑开挖引起的变形问题视为弹性半无限平面体平面应变问题。运用反对称映射原理,将基坑工程中支护结构对土体的作用荷载视为弹性半无限平面体中作用到土体的作用荷载。故将基坑中桩土界面处土体的侧向位移视为弹性半无限平面体中对称轴截面土体的位移,利用位移以Melan位移解计算出相应的分布荷载。得出分布荷载后,利用Melan位移解可计算出弹性半无限平面中任一点的位移,此位移即为基坑周围任一点土体的位移。以上过程即为本文提出的基于Melan解的桩、墙支护基坑土体变形的计算方法。(5)运用本文提出的计算方法对一深基坑工程进行计算,得到了合理的计算结果,验证了本法的可用性。
[Abstract]:With the continuous development of urban high-rise building and underground municipal engineering, the surrounding environment of foundation pit construction becomes more and more complex, which requires the control of the deformation of surrounding soil caused by foundation pit construction. Therefore, how to accurately predict the deformation of strata has become a more and more important problem in the design and calculation of foundation pit engineering. At present, the study of ground deformation caused by foundation pit excavation mostly focuses on predicting the surface settlement around the foundation pit, and rarely involves the deformation of soil below the ground surface, and most of them are empirical, semi-empirical method and lack of necessary theoretical basis. There is a large error in the calculation results. In order to solve this problem, a calculation method of ground deformation caused by foundation pit excavation based on Melan displacement solution is presented in this paper. The main research contents and achievements of this paper are as follows: (1) the correctness of Melan stress solution is verified by using equilibrium equation and stress geometric equation in elastic mechanics, and its errors are found and corrected. Then the corresponding displacement solutions are derived. (2) the formulas of displacement solutions obtained by different methods are studied, and the reasons for the difference are analyzed. According to the deformation characteristics of foundation pit excavation, a modified method of applying Melan displacement solution to foundation pit excavation problem is put forward. (3) by integrating the Melan displacement solution, the displacement solution under uniform element load is obtained. The deformation caused by foundation pit excavation is regarded as the plane strain problem of elastic semi-infinite plane body. (4) the deformation caused by foundation pit excavation is regarded as an elastic semi-infinite plane body plane strain problem. According to the principle of antisymmetric mapping, the action load of retaining structure on soil in foundation pit engineering is regarded as the action load of elastic semi-infinite plane body to soil mass. Therefore, the lateral displacement of the soil at the pile-soil interface in the foundation pit is regarded as the displacement of the symmetric axial section of the elastic semi-infinite plane, and the corresponding distributed load is calculated by using the displacement solution of the Melan displacement. It is concluded that the displacement of any point in the elastic semi-infinite plane can be calculated by using the Melan displacement solution after distributed load. This displacement is the displacement of any point of soil around the foundation pit. The above process is the calculation method of pile and wall retaining foundation pit soil deformation based on Melan solution proposed in this paper. (5) using the calculation method proposed in this paper, a deep foundation pit engineering is calculated, and the reasonable calculation results are obtained. The usability of this method is verified.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753
本文编号：2444316
[Abstract]:With the continuous development of urban high-rise building and underground municipal engineering, the surrounding environment of foundation pit construction becomes more and more complex, which requires the control of the deformation of surrounding soil caused by foundation pit construction. Therefore, how to accurately predict the deformation of strata has become a more and more important problem in the design and calculation of foundation pit engineering. At present, the study of ground deformation caused by foundation pit excavation mostly focuses on predicting the surface settlement around the foundation pit, and rarely involves the deformation of soil below the ground surface, and most of them are empirical, semi-empirical method and lack of necessary theoretical basis. There is a large error in the calculation results. In order to solve this problem, a calculation method of ground deformation caused by foundation pit excavation based on Melan displacement solution is presented in this paper. The main research contents and achievements of this paper are as follows: (1) the correctness of Melan stress solution is verified by using equilibrium equation and stress geometric equation in elastic mechanics, and its errors are found and corrected. Then the corresponding displacement solutions are derived. (2) the formulas of displacement solutions obtained by different methods are studied, and the reasons for the difference are analyzed. According to the deformation characteristics of foundation pit excavation, a modified method of applying Melan displacement solution to foundation pit excavation problem is put forward. (3) by integrating the Melan displacement solution, the displacement solution under uniform element load is obtained. The deformation caused by foundation pit excavation is regarded as the plane strain problem of elastic semi-infinite plane body. (4) the deformation caused by foundation pit excavation is regarded as an elastic semi-infinite plane body plane strain problem. According to the principle of antisymmetric mapping, the action load of retaining structure on soil in foundation pit engineering is regarded as the action load of elastic semi-infinite plane body to soil mass. Therefore, the lateral displacement of the soil at the pile-soil interface in the foundation pit is regarded as the displacement of the symmetric axial section of the elastic semi-infinite plane, and the corresponding distributed load is calculated by using the displacement solution of the Melan displacement. It is concluded that the displacement of any point in the elastic semi-infinite plane can be calculated by using the Melan displacement solution after distributed load. This displacement is the displacement of any point of soil around the foundation pit. The above process is the calculation method of pile and wall retaining foundation pit soil deformation based on Melan solution proposed in this paper. (5) using the calculation method proposed in this paper, a deep foundation pit engineering is calculated, and the reasonable calculation results are obtained. The usability of this method is verified.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753
【引证文献】
相关硕士学位论文 前2条
1 孔维美;深基坑带撑双排地下连续墙支护结构性状及其对邻近船闸的影响研究[D];华南理工大学;2018年
2 杨俭;珠海某深基坑开挖对邻近车站结构及其周围土体的影响分析[D];华南理工大学;2018年
，本文编号：2444316
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