Study On The Influence Of Shield Construction On Stratum Deformation And Surface Settlement Of Metro Tunnel

With the development of society and the acceleration of urbanization,China’s demand for urban transportation is growing.As a common means of transportation,subway plays an important role in alleviating traffic demand and expanding urban traffic network.To build the subway tunnel shield method is a commonly used method,high efficiency and easy to manage,but always in the construction of shield tunnel construction will cause certain influence to surrounding environment,especially the ground settlement caused by the problem,for the construction of city is very bad,easy to cause the building foundation is weak,when the settlement can also cause the facilities of deformation crack and even collapse.Therefore,it is necessary to study the influence of shield construction process on stratum deformation and surface settlement.Based on a range of shield in a tunnel project background as a case,through field monitoring and numerical simulation method to carry out the shield construction for the study of the deformation characteristics and the surface subsidence,and analyze the surface subsidence influencing factors,combined with the actual project to meet the corresponding surface subsidence control measures are put forward,the conclusion is as follows:1)By using numerical software to simulate and analyze the shield excavation process,the stress distribution characteristics and displacement change law during tunnel excavation are obtained.2)By regression analysis of monitoring data and modification of Peck formula,the maximum displacement correction coefficient a of surface settlement is0.9081～1.4069,and the width correction coefficient b of settlement trough is0.5402～0.6986,the surface settlement in this area can be better predicted.3)Study and analyze the influence of surface settlement under different spacing,different buried depths,different driving pressures and different grouting pressures during tunnel construction,and propose appropriate parameter Settings for the shield tunneling interval.4)Combined with the actual construction situation,control measures are proposed in two aspects of tunnel crossing different rock sections and construction design parameters,so as to control the surface settlement within a reasonable range.Figure [76] Table [15] Reference [82]...