Analysis On Stability And Deformation Of Foundation Pit Reinforced By Pre-stressed Anchor

This paper performs the research into anchor uplifting characteristics and foundation stability. After introducing its wide applications and the research progress about pre-stressed anchor system, detailed discussions on the three important methods for stability analysis are performed, the idea of finite element limit equilibrium method(FELEM) is introduced emphatically. On pre-stressed anchor system, the uplifting characteristics of single anchor is analyzed, on that basis analyzing deformation and stability of pit reinforced by pre-stressed anchor with FLAC(Fast Lagrange Analysis of Continue), and evaluate the impact of its parameters. Compared with results got through FLAC, FELEM obtain promising results, and also it is reasonable and has scalability itself. Therefore, FELEM will provide reference for engineering design and construction. The main work of this paper is:I:Consistent safety factor and slip surface are calculated with FLAC and FELEM;II:By comparing safety factor and sliding surface calculated by FLAC and FELEM for pre-stressed anchor supporting pit, it proves that FELEM can be used for assessment the stability of such supporting system.Ⅲ:Simulating the loading mechanism and failure modes of uplifting anchorIV:Analyzing the parameters'influence on stability and deformation:1) Pre-stress value put on the most obvious effect on deformation; the effect of anchor spacing on horizontal displacement and surface settlement is obvious; the smaller of anchor inclination angle the more helpful in controlling deformation, recommendation angle is 5°-10°; increasing anchor length can reduce horizontal displacement, but not surface subsidence.2) the failure mode of pit is mainly deep sliding that sliding surface through the anchors wholly or partly.