| Subway station, whose space is narrow and the surrounding environment is complex, ismostly located in the busy city. The strict control on excavation deformation of deepfoundation pit and decreasing it, will may increase unnecessary project cost, therefore, how toidentity between economics and security in deep foundation pit, has been an exploring topicin the geotechnical filed. Based on the in-situ monitoring, numerical simulation andoptimization design, this paper studyed the deformation of excavation and optimizing thepreliminary design in the deep pits of braced type station. It was composed of several aspectsas follows:Based on the results of the foundation pit engineering study and the pit project of EastYellow River Road Station in Zhengzhou, this paper analysised the horizontal displacementof pile, ground settlement and horizontal support system internal force in excavation process,and studyed the the deformation law of excavation of foundation.In order to understand the overall deformation of the pit in excavation process, the paperanalyzed the surrounding soil deformation and internal force change on support system indifferent conditions of the pit, considering the soil mass, fender pile and support system as awhole, and taking support structure and soil-soil interaction into consideration at the sametime, and made the comparative analysis of calculated results and measured data, based onnumerical simulation by finite element analysis means, it indicated the braced type systemwas suitable.The paper analysised the effect three parameters of support installation position, supporthorizontal spacing and support prestress to excavation process by finite element analysismeans, conclued the law and optimized the original supporting system design schemes of thestation foundation pit. Compared with the original projects, the deformation control andproject cost were greatly improved after optimization. |
