Study On The Control Of Surface Subsidence Caused By Subway Tunnel Excavation In Qingdao

With the rapid development of science and technology,various functions are brought together,and also more people are attracted to the city.The existing urban traffic pattern is difficult to evacuate people and support the healthy and sustainable development of the city.Coupled with the construction of smart city in recent years,it is the most feasible and effective way to develop the subway tunnel project for easing traffic jams,saving public land resources and promoting the process of urbanization.Because the subway tunnel is built in the densely constructed area,the deformation and movement of the ground surface during construction cause extra-stress on the upper building t,and also destroy its structural integrity and disturb people's stable life.In order to reduce or eliminate the negative influence of subway tunnel construction,The paper mainly studies the following aspects:(1)On the basis of expounding the current traffic jam and the adverse effects of subway tunnel construction,presenting the research significance and purpose of risk control of surface subsidence caused by subway tunnel construction and studying the current research situation of this problem both at home and abroad.(2)Firstly,analyzing the actual engineering case in this paper,that is the geological and hydrological conditions of river and river section of the Qingdao Subway;Secondly,summarizing the factors that affect the surface subsidence caused by the subway tunnel construction;finally,studying the negative influence of single factor such as geology,hydrology,design dimension,depth and so on to surface subsidence of the river and river section.(3)On the basis of studying and analyzing the concrete influence of surface subsidence on the above construction and the reinforcement measures for controlling surface subsidence,confirming the concrete measures for controlling the surface settlement of river and river section,namely,full face grouting and large pipe roof combined support.(4)Through laboratory test and field test,to determine the material liquid ratio of full face grouting and the grouting items during actual operation;Setting different parameters,to carry out the finite element numerical simulation by using Midas-GTS and to select the relevant parameters of the large shed support;Judging the rationality of the selected support measures by field monitoring data.(5)About a building located at the most unfavorable position above the earth's surface,simulating four kinds of working conditions by using Midas-GTS,that is without pre support,full section grouting pre support,large pipe shed pre support and whole section and large pipe combined support.Through comparing and analyzing the supporting effect,it is concluded that the combined support of the whole section and the large pipe shed can meet the relevant control standards.