Prediction Of Deformation And Study On The Influence Of Shield Tunnel On Adjacent Buildings

The shield method has been one of the main subway tunnel construction methods in domestic and foreign, however, shield construction may induce disturbance of soil within the construction influence scope and result in ground movements, excessive deformation will result in a series of environmental problems, such as the crack and collapse of the neighboring buildings. This thesis mainly adopts the method of field test and theoretical analysis to study the deformation and stress of the structure within the shield tunneling region. Main innovation work in this dissertation are listed as follows:(1) The main content in field test:Field test was adopted in the range of Datieguan Station-Zhanongkou Station engineering of Hangzhou metro line No1, this thesis studies the effects of shield tunneling on soil deformation and adjacent structure with different bases, especially the deformation of multistory building with shield tunneling below the short pile foundation(The First Car Company Coach Team office building), the deformation of adjacent building with shallow foundation (Wenhui Fruits Market Shops) and high building with long pile foundation(Yefeng Modern Home Resident Building)caused by shield tunneling.(2) The main content in theoretical analysis:1)Soil deformation:This thesis argues that the stratum loss caused by shield tunneling mainly includes which caused by the unearthed balance of excavation face, the gap of the shield tail and grouting. This thesis derives the formula of three-dimensional soil deformation in the semi-infinite space, and proposes the modified Sagaseta ground vertical deformation formula.2)Vertical deformation:Based on the modified Sagaseta ground vertical deformation formula, proposing the mechanical model and theoretical solution on the soil of shallow foundation building(short pile foundation)-foundation-structure interaction which located in the shield region. According to the shield region synergistic effect mechanical model, it is obtained the factors affects the deformation and internal force of structure, such as the structure stiffness, coefficient of subgrade reaction, the grouting ratio during tunneling, and so on.3)Horizontal deformation:This dissertation analyses on the laws of transverse subsidence of ground surface, and put forwarded the prediction formula of transverse subsidence of ground surface caused by shield tunnel construction adjacent buildings, such as:"plug-shaped curve","skewed distribution curve", and "normal distribution curve". Visualization software "The Effect System of Shield Tunnel Construction on Adjacent Structure" is compiled, and then it can judge the size of surface transverse sedimentation tank caused by tunnel excavation and the damage on adjacent structure.