黄土地区地铁隧道施工对邻近建筑物的影响分析

发布时间：2019-05-10 08:25

【摘要】：最近几年我国中西部地区在大力发展城市地下轨道交通,但是,我国中西部地区的地质情况决定了不能够直接使用以前在沿海发达地区地铁隧道或者山岭隧道的设计施工经验。本文对我国中西部黄土地区的城市地铁建设过程中对周边临近建筑物可能造成的不均匀沉降、建筑物倾斜、建筑物水平移动以及结构内力等方面的问题进行了分析,同时进行了距离参数和左右两隧洞的开挖顺序对建筑物的影响研究。为了分析黄土地区地铁隧道对临近建筑物的影响,本文在参考了大量相关文献的基础上,以正在建设的兰州地铁城市轨道交通一号线为研究背景,通过对隧道施工现场的黄土层进行取样分析,在室内试验取得黄土试样的各种实际参数。在确定了此黄土试样的各种相关特征性质后,运用ansys数值仿真分析软件,建立了框架结构在隧道施工过程中的计算模型,用来分析研究建筑物在隧道掘进过程中的沉降特征以及内力变化特征。本文中主要的研究内容及取得的成果如下:(1)在兰州地铁隧道的施工现场开挖出的掌子面上对黄土层原状土进行了取样,之后在实试验室通过含水率试验、密度试验、液塑限试验、渗透试验以及三轴压缩试验,可靠的取得了黄土试样的含水率、密度、液塑限、渗透系数、粘聚力以及内摩擦角等参数,保证了之后数值模拟的可靠性。(2)根据实际测得黄土试样参数,应用ansys软件建立了临近隧道的框架结构在隧道施工中的三维实体模型计算模型。对建筑物与地面接触的各个基点进行了竖向位移以及水平位移分析,然后对建筑物的倾斜进行了分析,最后对建筑物的结构内力的变化规律进行了有针对的分析。对建筑物在隧道施工过程中的不均匀沉降的特征、水平移动的规律、倾斜变化以及建筑物的结构内力在隧道掘进过程中的变化规律进行了研究。(3)通过改变隧道左右两个隧洞的开挖顺序,分析了在不同的开挖顺序下建筑物的位移、倾斜以及结构内力的变化特征。结果表明,先开挖距离建筑物较远的隧洞对建筑物的构件内力影响最小,而左右两条隧洞同时开挖时对控制建筑物的差异沉降最有利。(4)通过改变模型中建筑物的位置,进行了距离参数对建筑物影响的研究分析。对比了在不同距离参数下建筑物的位移变化情况、倾斜情况以及内力变化,为以后类似情况下的建筑物的位移变化、建筑物的倾斜和结构内力的预测提供一定的参考。
[Abstract]:In recent years, the central and western regions of China are vigorously developing urban underground rail transit. However, the geological conditions in the central and western regions of China determine that the previous design and construction experience of subway tunnels or mountain tunnels in coastal developed areas can not be directly used. In this paper, the problems of uneven settlement, building tilt, horizontal movement of buildings and internal force of structures in the process of urban subway construction in loess areas of central and western China are analyzed. At the same time, the influence of distance parameters and excavation sequence of left and right tunnels on the building is studied. In order to analyze the influence of subway tunnel on adjacent buildings in loess area, this paper takes Lanzhou Metro Urban Rail Transit Line 1 as the research background on the basis of referring to a large number of relevant literature. Through sampling and analysis of loess layer in tunnel construction site, various actual parameters of loess sample are obtained in laboratory test. After determining all kinds of related characteristic properties of the loess sample, the calculation model of the frame structure in the tunnel construction process is established by using ansys numerical simulation analysis software. It is used to analyze and study the settlement characteristics and internal force variation characteristics of buildings in the process of tunnel excavation. The main research contents and achievements in this paper are as follows: (1) the undisturbed soil of loess layer was sampled on the palm surface excavated at the construction site of Lanzhou Metro Tunnel, and then the moisture content test and density test were carried out in the real laboratory. The parameters of moisture content, density, liquid plastic limit, permeability coefficient, cohesion and internal friction angle of loess samples were obtained reliably by liquid plastic limit test, permeability test and triaxial compression test. The reliability of the subsequent numerical simulation is guaranteed. (2) according to the actual measured loess sample parameters, the three-dimensional solid model calculation model of the frame structure of the adjacent tunnel in tunnel construction is established by using ansys software. The vertical displacement and horizontal displacement of each base point in contact between the building and the ground are analyzed, and then the tilt of the building is analyzed. Finally, the variation law of the internal force of the structure of the building is analyzed. According to the characteristics of uneven settlement of buildings in the process of tunnel construction, the law of horizontal movement, The variation of tilt and the internal force of the structure of the building in the process of tunnel excavation are studied. (3) by changing the excavation sequence of the two tunnels around the tunnel, the displacement of the building under different excavation order is analyzed. The variation characteristics of tilt and internal force of the structure. The results show that the internal force of the building is the least affected by the excavation of the tunnel which is far away from the building, while the two tunnels are excavated at the same time to control the differential settlement of the building. (4) by changing the position of the building in the model, The influence of distance parameters on buildings is studied and analyzed. The displacement variation, tilt condition and internal force change of the building under different distance parameters are compared, which provides a certain reference for the displacement change of the building under similar conditions, the tilt of the building and the prediction of the internal force of the structure in the future.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

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