土质边坡板椅式桩板挡墙工作机理数值计算分析

Analysis on Working Mechanism of Board-chair Sheet Pile Retaining Wall at Soil Slope by Numerical Calculation

板椅式桩板挡墙是深厚斜坡软土地段路基边坡的一种新型支挡结构,亟需对其工作机理进行深入分析.运用ABAQUS有限元软件,建立了板椅式桩板挡墙的三维数值模型,对结构的内力变形、岩土体作用及主要影响因素进行了分析.结果表明：内力极值出现于桩梁交接处与岩土交界面附近,横梁需作为特殊构件设计;现有土压力分布假定基本能满足结构计算要求;覆土模量大于100 MPa或基岩模量大于10 GPa时,可不计岩土体参数对结构内力变形的影响;副桩布设于主桩内侧可有效降低椅式桩内力、转换桩基拉压属性,桩梁刚度比需控制在1-3范围内.

Board-chair sheet pile retaining wall is a new retaining structure used in soft soil section of deep slope for subgrade,and in-depth analysis on its working mechanism is required increasingly.With ABAQUS finite element software,a three-dimensional numerical model for this retaining wall was established to analyze the internal force and deformation of the structure,the rock-soil interaction and the main influencing factors.The results show that the extreme value of internal force appears in the junction of beam and pile,as well as near the interface between rock and soil,thus the beam is required to be designed as a special member; it is assumed that the existing soil pressure distribution may meet the requirement of structural calculation substantially; the influence of rook and soil parameters on the deformation and internal force of structure may be ignored when the overburden modulus is greater than 100 MPa or the bedrock modulus is more than 10 GPa;the arrangement of auxiliary piles set on the inner side of main piles can effectively reduce the internal force of the chair type piles,and transform the tensile and compressive properties of the pile foundation; the stiffness ratio of pile to beam should be controlled in the range of 1 to 3.