Risk Identification And Study On Deformation Laws Of Deep Excavation In Subway Station

Design of retaining structure and study of deformation laws of deep excavation isan important problem in the construction of subway station. It has important projectvalue to research the deformation laws of deep excavation of subway station. Relyingon the deep excavation of the subway station of WanShou road in Xi'an,thedeformation laws of deep excavation of subway station are studied with the methods oftheory analysis,in-situ monitoring,numerical simulation and risk identification. Thespatial effect of deep excavation was analyzed. The main content and conclusions areas follows:(1)The deformation principles and failure modes of retaining structure areanalyzed,and the main factors affecting the stability of deep excavationï¼›(2)It use the theory of unsaturated soil so as to simulate and analyzeprecipitation effects on the proposed site area and obtain variation of inside and outsidethe seepage pit in the process of precipitation. As a result,it provide the scientific basisfor optimization design of Precipitation scheme.(3)By the use of finite software Midas/GTS,a three-dimensional simulation ofthe entire process of excavation and support of deep excavation is accomplished. Thebehavior of retaining structure is analyzed,and the deformation laws of deepexcavation is studied in different cases:In two-thirds position of foundation pit excavation depth,soil and the level ofretaining structure deformation is the biggest of allï¼›With the increase of the depth of excavation,construction pile,the horizontal displacement of retaining structures and ground subsidence pits weeks showed agradually increasing trend:the more close to the foundation of the corner,the smallerenvelope of the horizontal displacementï¼›Support the axial force distribution shows an obvious spatial effect,the largestsupporting force in the middle of pit,away from the corner the more recent,the smallersupport forceï¼›(4)FTA analysis method is used to risk assessment and control in deepfoundation. By building the fault tree of the deep foundation pile anchors and carryingon qualitative and the quota analysis to it.we find the damage path and failure modeswhich can provide the reference for hazard identification and control of constructionhazard in deep foundation.