Research Of Interaction Between Shield Tunnel And Adjacent Structure

Hangzhou metro line No1 is planning to be constructed by using double-single round shield assembling configuration, whose total length is 61.095km and underground line is approximately 22.9km. The sector of shield tunnel mostly distributes in the main city zone of Hangzhou, along East railway station, Wulin square, Yanan road, Hangzhou railway station, Qiutao road, Fuchunjiang road, through the prosperous commercial area, where the buildings and underground ducts are crowded. Although shield tunnelling construction belong to one of methods by underground excavating, it still will be able to affect soil inevitably and distort soil, causing a series of geotechnical environment problems, such as the buildings inclining, cracking and collapsing and so on.This dissertation analyses and studies on the shield tunnel construction of adjacent structure, which includes: theoretical calculation and analysis of the soil settlement on the shield tunnel construction of adjacent structure; appraisal principle and standard of building on the shield tunnel construction; numerical simulation on the shield tunnel construction of adjacent structrue; control measure on the shield tunnel construction of adjacent structure. Main innovation work and viewpoint in this dissertation as follows:(1) This dissertation simplifies the stratum loss as the perturbation load on the shield construction, simultaneously considering the existence of the building load. Based on Boussineq solution of the elastic half-space, and obtains the biggest ground subsidence caused by the perturbation load function and the settlement caused by the building load. According to the principle of superposition and the Peck formula, it is obtained that the soil settlement is caused on the shield tunnel construction of adjacent structure.(2) The damage of adjacent structure on the shield tunnel construction is judged by establishing allowed soil settlement and soil loss, which determines the damage degree of building and whether to adopt the corresponding protective measure,through controlling of the curving and inclining distortion of building.(3) As a result of the difference of building foundation form, mutual influence between the shield construction and adjacent structure is also different. Based on Hangzhou metro line No1, FEM method is adopted in this dissertation to study and simulate on the shield tunnel construction of adjacent structure with two kind of different foundation, obtaining mutual influence rule of building and tunnel.(4) In Hangzhou metro line No1, the building protection will be adopted with the initiative control measure primarily on the shield tunnel construction, combining real-time monitor measure simultaneously. Suitable project measure will be taken promptly according to the actual situation on the shield tunnel construction so that the influence of tunnel excavation to building can be reduced least.