Research On The Effects Of Ground And Adjacent Pile Foundation Induced By Shield Tunneling

The economic of Hefei developed rapidly in recent years, in order to solve the traffic problems caused by urbanization, the city’s first metro project is under construction. The excavation of city subway tunnel will inevitably cause the surrounding soil’s disturbance, Thereby affecting the underlying of buildings or structures nearby. To prevent excessive surface subsidence from threatening the safety of ground surface and surrounding buildings, in-depth research and the reasonable control of ground movement and deformation of adjacent buildings, then formulate feasible control measures is of great practical significance. It is also particularly important to guide the following shield tunneling projects of Hefei and other similar areas.This paper takes Hefei subway line one between Taihu road Station and Nanyihuan Station shield tunneling construction engineering as background, for the surface subsidence and deformation of pile foundation caused by the shield construction research, made the following results.(1) Describes the Surface subsidence mechanism and the theory of finite element of Shield tunnel excavation;(2) The finite element analytical software ABAQUS have been used to build a plane model of tunnel excavation, based on Hefei soil parameters. It is considered separately that different tunnel depth, tunnel excavation diameter, lining thickness and modulus of elasticity, two-lane of tunnel construction impact on ground subsidence;(3) The international large finite element analytical software ABAQUS was employed to build a2-dimensional elastic-plastic model.In the2-dimensional simulation with the add-remove method, different soil layers, nonlinearity of the soil, interaction between liner and soil, pile and soil are all considered. This paper explored the effects of adjacent pile foundation induced by shield tunneling;(4) On the basis of the previous model, explored the influence of pile when its parameters changed, such as, pile length, pile spacing, pile diameter, pile load, double-pile foundation, two-lane tunnel excavation, and so on;(5) Comparison of the field monitoring data and numerical simulation results, verified the feasibility of the numerical simulation of surface subsidence prediction.Combined with the actual construction parameters, proposed the effective measures to control the deformation of ground and pile foundation in shield tunnel construction, got some useful conclusions.