Study of Supporting Structural Stability for Riverbank Deep Foundation Pit under Seepage

When riverbank deep foundation pit is excavated,the river radial seepage will have significant impact on the stability of deep foundation pit and supporting structure. For exploring the law of seepage during the excavation of riverbank deep foundation pit,the numerical simulation analysis is used for a deep foundation pit engineering. A three-dimensional model for coupling problem of seepage and stress fields is established. The results reveal the force and deformation law of the surrounding soil of the pit and supporting structure with the seepage in the deep foundation pit. The results show that: 1 at the initial water level,the effect of seepage on horizontal stress and shear stress of surrounding soil is small,but when water level rises,horizontal stress in soil at pit bottom significantly increases,stress concentration is outstanding at the corner of pit wall,and the largest value of shear stress appears beneath the corner of the pit; 2 the horizontal and vertical displacements of surrounding soil monotonously increase when the water level rises; 3 the pile moment and shear force increases obviously in the early stage of water level rising,and then level off; 4 axial force of free and anchorage section of the upper and lower anchors increases significantly in the early stage of water level rising,and then level off; 5 the coefficient of safety has a great reduce in the early stage of water level rising and then decreases linearly with a small rate.