锚杆支护吸能调控效应理论解析与数值模拟

Theoretical analysis and numerical simulation of energy absorption and control effect of bolt support

为揭示锚杆的支护吸能调控效应及巷道围岩能量场分布规律,采用理论分析、数值模拟方法研究了锚杆支护巷道围岩能量分布特征。首先,采用经典的弹塑性理论及能量守恒定律,分析了支护巷道围岩弹性变形能、耗散能和外力功之间的关系,给出了锚杆吸能表达式;其次,基于有限差分FLAC3D软件及内嵌的Fish语言编程,开发了能量单元模块,模拟揭示了锚固体的预应力扩散和释能特性;再次,通过单元网格遍历循环的方式计算了巷道围岩中各岩体单元的能量,获得了巷道围岩总变形能、弹性变形能和耗散能的数值及分布特征;最后,揭示了开挖与锚杆支护条件下巷道围岩能量场分布规律,从能量调控角度确定了锚杆合理的长度、间排距等支护参数。研究结果表明:锚杆主要以提高围岩体力学参数及转化吸收能量的方式来调控巷道围岩能量场的分布和耗散特征;随着锚杆间排距缩小和锚杆长度增大,巷道围岩最大耗散能密度呈降低趋势。

To reveal the energy absorption and regulation effects of bolt support and the energy field distribution in roadway surrounding rock,theoretical analysis and numerical simulation methods were employed.Firstly,using classical elastoplastic theory and the energy conservation law,the relationships among elastic deformation energy,dissipated energy,and external work in supported roadway surrounding rock were analyzed,deriving an initial expression for bolt energy absorption.Secondly,based on FLAC3D software and embedded Fish language programming,an energy unit module was developed to simulate the prestress diffusion and energy release characteristics of anchorage bodies.Thirdly,by traversing the element grid,the energy of each rock unit was calculated,and the total deformation energy,elastic deformation energy,and dissipated energy and their distribution characteristics were obtained.Finally,the energy field distribution was revealed under excavation and bolt support conditions.Reasonable bolt parameters was determined,such as length and spacing.The results show that bolts primarily regulate the energy field distribution and dissipation characteristics of roadway surrounding rock by enhancing the mechanical parameters of the rock mass and converting absorbed energy.As the bolt spacing decreases and the bolt length increases,the maximum dissipated energy density in the surrounding rock of the roadway tends to decrease.