Influence of pit bottom reinforcement on deformation of long and narrow foundation pits in deep soft soil
To study the effect of pit bottom reinforcement on the deformation of foundation pit and surrounding environment,Guangzhou Nansha port railway open-cut tunnel deep soft soil narrow-long foundation pit is taken as an example,a typical foundation pit section is selected to establish a three-dimensional calculation model,and the rationality of finite element calculation is verified by comparing the results of field monitoring and numerical simulation.Based on this model,the influence of modification of soil reinforcement parameters and bearing pile reinforcement design parameters of the passive area on the deformation of foundation pit is explored.The results show that the soil reinforcement of the pit bottom has a significant influence on the control effect of the deformation of foundation pit,the effect of reinforcement width and reinforcement depth is equal,and the horizontal displacement of wall can be controlled by 35%～40%,the reinforcement depth is recommended to be 0.15H～0.31H(H equals to the excavation depth of the foundation pit),and the reinforcement width is recommended to be 0.61H～0.92H,when the effective range is exceeded,the reinforcement effect becomes no longer obvious;the effect of bearing pile reinforcement on the control of deformation of foundation pit is not different,the horizontal displacement and surface settlement of the wall would decrease with the increase of pile length and pile diameter,with the increase of pile spacing,the horizontal displacement of the wall shows a trend of increasing,which is not conducive to the control of deformation of foundation pit,but the surface settlement increases in a near-linearly manner,and the change rate is relevantly small,the maximum settlement position is about 0.77H from the edge of the foundation pit,and the main influence range is about 3.0H.The research results can provide reference for the control of deformation of foundation pit in soft soil areas and similar engineering reinforcement design.
railway tunnelpit bottom reinforcementdeformation of foundation pitfield monitoringnumerical simulation
NETL
NSTL
万方数据
