Study On Shield Tunneling Induced Ground Surface And Buildings Settlements In Water-bearing Soft Soil

Shield construction used in subway tunnel construction of the city is very popular, and controling surface settlement and building settlement is an important task in subway construction.The related settlement can be divided into two parts:sedimentation during construction and consolidation settlement, then how to predict and control sedimentation during construction and subsequent consolidation settlement is an important topic of metro shield tunnel construction. Combining with shield tunneling practice of Suzhou Rail Transit Line2, this paper, mainly for characteristics of weak strata, carryed out some research which is more in-depth about law of surface settlement and building settlement in long-term because of shield tunnel construction by theoretical prediction, optimization, the measured data analysis, and summary of the law.(1)According to domestic and foreign datas, this paper studyed long-term surface settlement and building settlement caused by shield tunnel construction. The studies of long-term settlement using a time-phased research approach, setting the long-term settlement into sedimentation during construction and subsequent settlement and the same time it does the relevant review for two types of settlement.(2)The law of surface settlement and building settlement during the consolidation was studied. This paper described the mechanism of surface settlement caused by shield tunneling through ground loss theory and pore water pressure theory, and explored the factors and laws that influence surface settlement. Also it studied the impact of shield tunneling mechanism to neighboring buildings, factors caused settlement and buildings suffererd damage in specific ways.(3) Theoretical study of subsequent settlement was introduced. It did analysis of main factors causing subsequent settlement in shield tunneling, made comparison of all kinds of theoretical calculations of subsequent settlement. And by combineing with Suzhou Metro Line2project examples, and optimizing subsequent settlement calculation, it gained suitable settlement program in Suzhou.(4) In this paper, a large number of engineering test data was taken into analysis, so the law of the surface and building’s subsequent settlement was summed up.