Research On The Control Of Deformation During Construction Of Deep Excavation Adjoining Operating Metro Station

With the development of urban rail transit network in Shanghai, the construction of interchange connections will be a new technical problem for building the whole rail transit network, especially when the built station has no structural measures in advance, high risk will be confronted by the newly constructing station. In this dissertation, by using the designing theories of deep foundation pit which has asymmetric environment protection level, the research on the calculating models of the built station's deformation and internal forces caused by the newly constructing station, the evaluation of calculating parameters, the protecting measures of the built station, and the control of the differentia settlement between old and new stations is carried through on the basis of the construction of the People's Square station in Shanghai M8 Metro Line. The chief work is summarized as follows:1. when the deep foundation pit of a newly building metro station has asymmetric environment protection level, constructing cost will be increased if the station is designed to meet the higher environmental protecting level. To solve that problem, some designing and constructing measures are brought forward to make the bracing of deep foundation pit deform asymmetrically, the entire and separate structure loading models in designing such metro deep foundation pit are established, and the method of evaluating the parameters concerned in those two models is given.2. according to the real situation of projects, by using the separate structure loading model to calculate the deformation of the bracing of deep foundation pit which has asymmetric environment protecting level, the research on the calculating method of the built station's deformation which caused by the newly constructing station in parallel interchange connections is carried through from the angle of soil engineering properties and mechanics, then the reaction of the built station caused by the newly constructing station is simulated by making use of the established calculating model, and the calculating results are relatively accordant with measuring ones.