“预应力锚杆围岩”锚固体系承载效应及力学分析

Bearing effect and mechanical analysis of the anchoring system of"prestressed anchor bolt-surrounding rock"

针对巷道围岩变形和应力不协调的工程问题,采用理论分析和数值模拟的方法对“预应力锚杆围岩”锚固体系的应力分布规律和影响因素进行系统研究。研究认为:锚杆预应力可有效改善围岩应力环境,锚杆长度越长、间排距越小,对围岩的控制效果越好,在浅部围岩形成明显的压应力区,可有效控制巷道变形;锚固剂及锚杆构件直接影响锚固体系的应力分布,球形托板扩散预应力的效果要明显优于平板托板,锚固段尾部至锚固段端部区域内应力值变化规律呈现出指数曲线特征。研究成果可为锚杆支护设计提供理论依据。

In view of the inharmonious engineering problem of surrounding rock deformation and stress,the stress distribution and influencing factors of"prestressed anchor bolt-surrounding rock"anchoring system are systematically studied by theoretical analysis and numerical simulation.The results show that the prestress of bolts can effectively improve the surrounding rock stress environment,the longer the length of bolt and the smaller the row spacing,the better the control effect on surrounding rock,and the obvious compressive stress zone is formed in the shallow surrounding rock,which can effectively control the deformation of roadway.The anchorage agent and bolt member directly affect the stress distribution of the anchorage system.The effect of diffusion prestress of the spherical plate is obviously better than that of the flat plate.The variation of stress value in the area from the end of the anchorage section to the end of the anchorage section shows an exponential curve.The research results can provide theoretical basis for bolt support design.