地铁隧道盾构法施工引起的地表沉降分析和规律研究
发布时间：2019-05-18 14:25
【摘要】：随着我国经济的发展,为缓解严重的城市道路交通问题和发展城市公共交通,城市地铁建设数量越来越多。由于城市市区内易受施工影响因素较多,盾构法以其施工优势及对周边环境影响较小而被广泛采用。但施工过程会不可避免的引起地表沉降,地表沉降不仅影响施工安全,同时影响道路、建筑物等安全。本文结合北京昌平线二期工程的3个盾构项目标段,对由不同机型土压平衡式盾构穿越不同的土层引起的地表沉降进行了分析。首先对实测地表沉降数据进行分析,同结论:(1)盾构穿越不同土层引起的横向沉降槽均近似服从正态分布;若有较大的外部因素影响,横向沉降槽将发生偏移。当模拟参数取值与实际工程相符时,数值模拟能够很好的反映地表沉降规律。(4)土层沉降随着隧道埋深的增加而逐渐减小,空间效应明显。但是在盾构隧道覆土中卵石层较厚的区域,土层扰动范围扩展较大。时总结了盾构施工参数与地表沉降之间的关系。然后运用有限元软件Midas GTS模拟3条盾构隧道,对模拟数据进行分析,并与实测数据进行比较。得出了以下(2)地表沉降量与盾构穿越土层有关。当盾构穿越卵石层时,地表沉降量为-16.2mm;盾构穿越粉质黏土层时,地表沉降量在-8.5mm左右。(3)地表沉降最终沉降槽在形成过程中具有明显的阶段性,可划分为三个阶段,各阶段产生的地表沉降量分别为:盾构机到达前,地表沉降量为总沉降量的5—10%,盾构机通过过程中产生的沉降量为总沉降量的60—70%,盾构机通过后的沉降量为总沉降量的占20—35%。但穿越不同的土层,盾初期沉降量和盾构通过时的沉降变化速率明显不同。
[Abstract]:With the development of economy in China, in order to alleviate the serious urban road traffic problems and develop urban public transport, the number of urban subway construction is increasing. Because there are many factors that are vulnerable to construction in urban areas, shield method is widely used because of its construction advantages and little impact on the surrounding environment. However, the construction process will inevitably cause surface subsidence, which not only affects the construction safety, but also affects the safety of roads, buildings and so on. Based on the three shield section of the second phase project of Changping Line in Beijing, this paper analyzes the surface subsidence caused by different types of earth pressure balanced shield passing through different soil layers. Firstly, the measured surface subsidence data are analyzed, and the same conclusion is as follows: (1) the transverse subsidence trough caused by shield passing through different soil layers approximately obeys the normal distribution, and if there are great external factors, the transverse settlement trough will shift. When the simulation parameters are consistent with the actual engineering, the numerical simulation can well reflect the law of surface subsidence. (4) the settlement of soil layer decreases gradually with the increase of tunnel depth, and the spatial effect is obvious. However, in the area where the pebble layer is thicker in the shield tunnel overlying soil, the disturbance range of the soil layer is larger. The relationship between shield construction parameters and surface subsidence is summarized. Then the finite element software Midas GTS is used to simulate three shield tunnels, and the simulation data are analyzed and compared with the measured data. It is concluded that the following (2) the surface subsidence is related to the shield passing through the soil layer. When the shield passes through the pebble layer, the surface subsidence is-16.2mm. When the shield passes through the silty clay layer, the surface subsidence is about-8.5mm. (3) the final subsidence trough of the surface subsidence has obvious stages in the process of formation, which can be divided into three stages. The surface subsidence produced in each stage is as follows: before the arrival of the shield machine, the surface settlement is 5 鈮，
本文编号：2480080
[Abstract]:With the development of economy in China, in order to alleviate the serious urban road traffic problems and develop urban public transport, the number of urban subway construction is increasing. Because there are many factors that are vulnerable to construction in urban areas, shield method is widely used because of its construction advantages and little impact on the surrounding environment. However, the construction process will inevitably cause surface subsidence, which not only affects the construction safety, but also affects the safety of roads, buildings and so on. Based on the three shield section of the second phase project of Changping Line in Beijing, this paper analyzes the surface subsidence caused by different types of earth pressure balanced shield passing through different soil layers. Firstly, the measured surface subsidence data are analyzed, and the same conclusion is as follows: (1) the transverse subsidence trough caused by shield passing through different soil layers approximately obeys the normal distribution, and if there are great external factors, the transverse settlement trough will shift. When the simulation parameters are consistent with the actual engineering, the numerical simulation can well reflect the law of surface subsidence. (4) the settlement of soil layer decreases gradually with the increase of tunnel depth, and the spatial effect is obvious. However, in the area where the pebble layer is thicker in the shield tunnel overlying soil, the disturbance range of the soil layer is larger. The relationship between shield construction parameters and surface subsidence is summarized. Then the finite element software Midas GTS is used to simulate three shield tunnels, and the simulation data are analyzed and compared with the measured data. It is concluded that the following (2) the surface subsidence is related to the shield passing through the soil layer. When the shield passes through the pebble layer, the surface subsidence is-16.2mm. When the shield passes through the silty clay layer, the surface subsidence is about-8.5mm. (3) the final subsidence trough of the surface subsidence has obvious stages in the process of formation, which can be divided into three stages. The surface subsidence produced in each stage is as follows: before the arrival of the shield machine, the surface settlement is 5 鈮，
本文编号：2480080
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