Numerical Analysis Of The Influencing Factors Of Supporting Structure And Soil Deformation Caused By Foundation Pit Precipitation

Along with the urban density increasing, the distance between buildings has been reduced to the limit, consequently, improve the relevant requirements of the foundation pit supporting. The settlement of the buildings around the foundation pit require the corresponding control to the horizontal displacement of foundation pit, This requirement also put forward some challenges. Meanwhile, the settlement caused by foundation pit precipitation may be natural different as a result of diverse soil permeability coefficient. So the influencing factors of settlement caused by the foundation pit supporting and precipitation is quite some, even the interaction between these factors. These factors play an important role in settlement control of deep foundation pit or foundation pit of settlement control strictly, How can consider comprehensively and reasonably these factors in support and precipitation of foundation pit, is a problem that be worth researching and solving.In order to study the influence of the horizontal displacement and the settlement of surrounding soil caused by various parameters in the precipitation process. In this paper, the settlement of foundation pit precipitation, soil and foundation pit stability theory research are carried on the detailed elaboration, and use the FLAC3D4.0modeling, at the same time, it contains seepage calculation module. Using those measures research and analysis the settlement of surrounding foundation pit soil caused by the precipitation and excavation, it is concluded the extent of the effect of the relevant parameters.(1)This paper analyzes parameters impact to continuous wall moment, soil subsidence, lateral displacement and a shaft supported force during the precipitation and excavation process. The parameters include changing the Pit Supporting Structure underground continuous wall modulus, changing the position of the support in the Pit Supporting Structure, head difference between the inside and outside and the Pit Supporting Structure.(2)Beside, the paper contrast Mohr-Coulomb the models and Cysoil model calculations in FLAC3D, and come to result that the difference between the calculate results of the two models and application effect.According to the above analysis concluded:(1)Compared with C-Y model and M-C model, the bending moments and the supporting force have little difference in the range of10%to about25%, the deformation value have larger difference. Sedimentation is maximum in C_Y model; horizontal displacement is maximum in M-C of model; rebound is maximum in M-C model. (2) When the modulus of the continuous wall change, the bending moment of the wall with the modulus increases; subsidence and horizontal displacement with the modulus decreases; total supporting force almost unchanged.(3)With the lowering of the water level in the pit outside, the continuous wall moment and support axial force will be dropped significantly, horizontal displacement and surface subsidence also dropped significantly.(4)With increasing soil modulus, continuous wall moment and deformation decreases, the soil modulus increases to3times, bending moment decreased by15%, the settlement is reduced by30%, the horizontal displacement is reduced by25%, the support shaft force change little.(5)The support position change can optimize a continuous wall and supporting axial force, increase a support can significantly reduce the continuous wall bending moment and deformation of the pit.(6)The hydrodynamic pit outside pressure is less than the precipitation pressure; pit hydrodynamic pressure greater than precipitation pressure; pit hydrodynamic pressure will reduce the effective stress of the soil, increase the bottom of the pit uplift risk, anti-seepage and anti-uplift are interrelated.