Ground Deformation Measurement And Three-dimensional Numerical Simulation And Parametric Analysis By Shield Driven

Shield is an important method of the tunnel construction in soft soil, however, itwould certainly cause various degrees of effect on the surrounding soil no matterwhich way be taken. In this paper, the surrounding soil disturbance mechanism andthe causes of it are analyzed, and the surrounding soil stress-strain disturbance and thefactors that cause land subsidence have been discussed.FEM is an important way of tunnel excavation calculation, with the mathematics andmechanics research methods, this paper studies the FE numerical calculation of soildeformation caused by tunnel excavation. With the background of Tianjin No. 1subway project and Guangzhou No. 2/8 extension subway project, the field test ofground settlement and tilted have been processed. Based on the field test on horizontaland vertical displacement of each layer, the 3D dynamic tunnel excavation model hasbeen simulated by ABAQUS program, considering by the material nonlinearity, thegap of shield empennage, earth pressure in shield airtight cabin, the interaction ofsurrounding soil and lining structure. The field measurement data shows that the FEcalculation is given a good match on the measured results.In this paper, large-scale general nonlinear FE analysis program ABAQUS has beenadopted for numerical simulation. The dynamic tunnel excavation model has beenbuilt by a comprehensive consideration on key factors such as soil non-linearity, theinteraction of soil and lining, grouting pressure and the supporting pressure. Thispaper analyses the law of deformation on ground and each layer as well as thesurrounding soil caused by tunnel excavation, and the effects on result caused byvarious factors such as pressure support, pressure grouting, as well as the stiffnessreduction coefficient.This paper employs equivalent load to simulate the building, which possessingshallow foundation upon the tunnel. This paper also analyses the ground deformationas well as the effect of shallow foundation in different sizes and locations. Finally, thevarious characters of soil have been studied in the condition of parallel with the tunnelexcavation to a certain distance interval.The research of this paper offers the reliable basis for the choice of parameters ondesign and construction of tunnel excavation, and also provides the technical supportfor the forecast of ground during tunnel excavation.