Optimization Parameter Study On Surface Settlement Control Induced By Shield Tunneling In Water-Rich Gravel Stratum

With the speeding up of urbanization in our country, urban problems such as traffic congestion, environmental pollution is increasingly serious, only consider the development of the city will be blocked from the ground. So it is urgent to solve these problems, experts started to focus on the development and utilization of urban underground space, the priority to the development of urban public transportation is the effective way to solve the problem of urban traffic, subway arises at the historic moment, the shield tunnel construction with its advantages of high safety coefficient and fast construction become the first choice construction method for the construction of urban subway. however the subway construction inevitably disturbed the surrounding strata, causes the surface subsidence, Affect safety of the ground and surrounding buildings, so according to the engineering geology, water and other conditions, select the reasonable control of shield construction parameters is very important.This paper takes the control of surface s settlement in water-rich gravel stratum as the background, with subway shield interval of Convention center station to Century plaza station in shen yang, adopting the method of in-situ test and finite element simulation, optimization research on shield construction parameters, as soil warehouse pressure, grouting pressure and unloading disturbance by soil mass of cutting wheel front, finally summed up the reasonable of construction control parameters. The main research content is as follows:(1) It Introduces the time and space effect of strata movement, the mechanism of ground movement and surface subsidence law induced by shield tunnel construction, from two aspects of horizontal and vertical settlement through analyzing the rule of ground subsidence, analyzes the influence factors of ground surface deformation and control measures of surface settlement.(2) Establishing a 3 d finite element model based on subway shield interval of Convention center station to Century plaza station in shen yang, dynamic simulating the construction process of shield tunnel excavation, for the soil warehouse pressure, grouting pressure and unloading disturbance degree of single factor analysis, optimization study on control parameter by shield tunneling construction in water-rich gravel stratum.(3) the results of Numerical simulation were compared with the measured data, verifying the rationality of the optimized parameters, can be used as the reference to the similar engineering construction.