Numerical Simulation Analysis Of Surface Settlement Caused By ZhengZhou Subway Tunnel Shield Construction

With the rapid development of modern cities and the shortage of land resource.,the contradiction between the speed of urban development and the land resources is becoming more and more serious.In order to make full use of the limited land resources,people constantly innovate in the development and improve the building height,making the utilization rate of the unit land area increase rapidly.The rational development and utilization of underground space further increase people's activity area.The production of subway is to further improve the utilization efficiency of underground space and alleviate the pressure of ground traffic.Shield method is the most commonly used method In the construction of the subway at present.The popularity of the shield method is mainly because of its unique advantages and characteristics during the construction of the subway.During the construction of subway tunnel with shield method,the field construction will cause the settlement or uplift of the land surface.It is possible that there will be a small amount of the land surface deformation as time goes on.The number of surrounding structures and underground pipelines,which are affected by the settlement of the earth's surface every year,is very large,and economic losses caused can't be ignored.Therefore,it is very urgent and necessary to discuss and analyze the deformation of the land surface caused by subway tunnel constructed by shield method.Based on a large number of relevant documents,this paper will carry out some research on the surface deformation caused by subway tunnel constructed by shield method.First,the theory of predecessor's research on this content is summarized,and the empirical method,numerical simulation method and different influencing factors of construction parameters are analyzed.Then,according to The tunnel section of the Hexi North Road Station of the starting station of Zhengzhou Metro Line 4 as the engineering background,and a soil layer is selected from the tunnel.A 3D analysis model of numerical analysis is established by using the finite element analysis software MIDAS/GTS.The process of shield advance is simulated,and the land surface settlement caused by the process of shield advance is analyzed.Through the analysis and discussion,some conclusions with reference value can be used to guide the construction of the later period:1.For the double line shield tunnel construction,one side construction will disturb the soil around the other side of the tunnel,resulting in greater disturbance of the soil on the other side of the tunnel during construction.2.The surface sttlement curve will be "shuangfeng" When the shield tunneling is advancing on one side.3.The lateral settlement of the tunnel surface is more affected by the construction steps4.With the continuous advance of the shield,the disturbance of soil is greater5.The surface subsidence of the shield tunnel is mainly above the axis of the tunnel,and the influence of 5D is very small...