根据黄河下游河道特点和河道整治工程情况，对移动式管桩在应用于潜坝和基坑支挡结构时的内力采用数值模拟方法进行了分析，建立了管桩、土和水的FLAC3D模型，对管桩嵌固深度进行了校核，分析了各种工况下管桩的桩身位移和内力，并模拟管桩修作基坑支挡结构时的受力状态。结果表明：①用作透水桩坝的管桩在动水压力、桩前后静水压力差及土压力的作用下，管桩上部向背河方向移动，当冲刷深度为14 m时为最不利受力状态，冲刷深度对桩体内力影响较大；②用作不透水桩坝的管桩在动水压力、桩前后静水压力及土压力的作用下，管桩上部向背河方向移动，桩顶位移很小，桩体最大弯矩和最大剪力均较小，当管桩发生顶面溢流时管桩上部向背河方向移动，桩体内力和桩顶位移均较小，管桩稳定性增强；③将管桩用于基坑支挡结构时，桩体内力和桩顶位移均能满足一般基坑支护的要求；④为保证桩坝无论在洪水期还是枯水期都能保持稳定，必须增大桩体的嵌固深度。%It was analyzed on the embedded depth, displacement and internal force of movable pipe pile in the submerged dam and retaining structure of foundation pit and stresses state of retaining structure by FLAC3D method, according to the characteristics of the lower Yellow River. The results show that a) the upper pile is moving to the opposite of the river and the scour depth has greatly affected internal force when it is 14 m;b) the displacement, the maximum bending moment and the maximum shear force of the pile of the movable pipe pile are small when it is under the stress of dynamic water pressure, hydrostatic pressure and earth pressure;c) the internal force and displacement of the pile can meet the requirements of the general foundation pit support when the pipe pile is used in the retaining structure; d ) the embedded depth of pile must be increased in order to ensure the pile dam stable both in flood period and dry season.
展开▼
