排桩支护结构内力与变形三维有限元数值分析

Three-dimensional finite element analysis of internal forces and displacement of scattered row piles

针对离心模型试验建立了三维有限元数值模型,通过与试验的比较验证了模型的可靠性,并与规范法中的m法进行了比较分析。结合一个悬臂排桩支护结构实例分析了桩身截面尺寸、桩间距和土体强度参数对桩身内力和变形的影响规律。研究表明:采用m法进行排桩支护结构设计偏于保守,与m法相比三维有限元法计算结果与离心机试验结果更为接近;桩身弯矩和桩顶水平位移随桩间净距的增加和桩身截面宽度的减小近似呈线性增加,随着土体黏聚力和内摩擦角的增加近似呈指数形式增加。

A three-dimensional Finite Element Model（FEM）of centrifuge was established first,and the reliability of the model was validated by centrifuge test.Then this method was compared with the current specified m-method.A case study of cantilever row piles was carried out to analyze the impact factors to the internal force and head horizontal displacement of the pile.These impact factors include the cross-section area of the pile,the pile spacing and soil strength.Results show that the design of row pile retaining structure by the m-method is conservative.The three-dimensional FEM method is more consistent with the centrifuge testing results than the m-method.The bending moment and the horizontal displacement of the pile linearly increase as the pile spacing increases and the pile width decreases.They nearly exponentially increase with the cohesion and internal friction angle of the soil.