【摘要】：隨著城市高層建筑和地下市政工程的不斷發(fā)展,基坑工程施工周邊環(huán)境也越之復雜,這就要求對基坑施工引起的周圍土體的變形進行控制。因此,如何準確預測地層的變形成為基坑工程設計計算中一個越來越重要的問題。目前,對基坑開挖引起的地層變形的研究多集中在預測基坑周圍地表沉降,很少涉及地表以下土體的變形,且多為經(jīng)驗、半經(jīng)驗方法,缺乏必要的理論依據(jù),計算結果存在較大的誤差。針對這一問題,本文提出一個基于Melan位移解的基坑開挖引起的地層變形的計算方法。本文的主要研究內容及成果如下:(1)運用彈性力學中平衡方程、應力幾何方程對Melan應力解正確性進行驗證,發(fā)現(xiàn)其錯誤并進行更正,然后推導出其相應的位移解。(2)研究了由不同方法得到的位移解公式,分析了造成差異的原因。針對基坑開挖時的變形特點,提出將Melan位移解用于基坑開挖問題的修正辦法。(3)通過對Melan位移解進行積分,得到單元均布荷載作用下的位移解,用以模擬基坑開挖時使土體產(chǎn)生變形的作用荷載。(4)將基坑開挖引起的變形問題視為彈性半無限平面體平面應變問題。運用反對稱映射原理,將基坑工程中支護結構對土體的作用荷載視為彈性半無限平面體中作用到土體的作用荷載。故將基坑中樁土界面處土體的側向位移視為彈性半無限平面體中對稱軸截面土體的位移,利用位移以Melan位移解計算出相應的分布荷載。得出分布荷載后,利用Melan位移解可計算出彈性半無限平面中任一點的位移,此位移即為基坑周圍任一點土體的位移。以上過程即為本文提出的基于Melan解的樁、墻支護基坑土體變形的計算方法。(5)運用本文提出的計算方法對一深基坑工程進行計算,得到了合理的計算結果,驗證了本法的可用性。
[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.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TU753

【引證文獻】

相關碩士學位論文 前2條

1 孔維美;深基坑帶撐雙排地下連續(xù)墻支護結構性狀及其對鄰近船閘的影響研究[D];華南理工大學;2018年

2 楊儉;珠海某深基坑開挖對鄰近車站結構及其周圍土體的影響分析[D];華南理工大學;2018年

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本文編號：2444316