抗沟渠型空洞水平加筋体的作用机理及设计方法

Action Mechanism and Design Method of Horizontal Reinforcement Subjected to Trench Void

考虑上覆土体的土拱效应及水平加筋体的大变形,将下卧土体沟渠型空洞条件下的水平加筋体分为滑动区和空洞区,并建立了其受力变形分析模型。利用该分析模型研究了滑动区水平加筋体界面强度、水平加筋体上覆土体的厚度和有效内摩擦角以及水平加筋体刚度对水平加筋体受力变形的影响。在此基础上,以水平加筋体的最大拉应变作为控制标准,建立了工程上抗沟渠型空洞的水平加筋体设计方法。结果表明:上覆土体厚度和有效内摩擦角对水平加筋体受力变形的影响很大,而水平加筋体的抗拉刚度直接决定了其拉应变的大小。

Taking into account the soil arching effect of overlaying soil and the large deformation of the horizontal reinforcement, the analysis model was presented for the force and deformation of horizontal reinforcement subjected to the trench void by dividing the horizontal reinforcement into the sliding area and the void areas. Influences of interface shear strength of the horizontal reinforcement, the thickness and the effective internal friction angle of the overlaying soil as well as the tensile stiffness of the horizontal reinforcement on force and deformation of horizontal reinforcement were studied by the proposed model. Based on it, taking the maximal tensile strain of the horizontal reinforcement as the control parameter, the design method of the horizontal reinforcement subjected to trench void was given for the engineering application. The results show that the thickness and the effective internal friction angle of the overlaying soil can heavily influence the force and deformation of the horizontal reinforcement, and the tensile strain of the horizontal reinforcement mostly depends on its tensile stiffness.