围岩松动圈敏感因素解析分析

Theoretical analysis on the sensitive factors of broken rock zone

采用解析方法,分析讨论了巷道围岩进入破裂状态后围岩内的应力分布以及围岩松动圈范围的计算方法,在此基础上,重点采用MATLAB软件,利用控制变量法分析了影响围岩松动圈范围大小的敏感因素,是对围岩松动圈巷道支护理论的补偿和完善。论文获得以下主要结论:①在理想弹塑性情况下,是无法确定松动圈范围的大小,而利用塑性位势理论求出塑性应变并补充径向应变在松动圈与塑性区交界处相等的条件就可以确定松动圈范围的大小;②影响松动圈范围的敏感因素是原岩力学参数和原岩应力,而支护力和松动圈内围岩的粘聚力对松动圈范围的影响较弱;③松动圈内围岩的粘聚力在有限范围内对松动圈范围影响显著,注浆加固可有效提高围岩的粘聚力,进而可在有限限度内减少松动圈范围;④理论上证明了支护力对松动圈范围的影响较小,在现有支护条件下可忽略不计。

The analytical method was used to analyze and discuss the stress distribution in the surrounding rock and the calculation method of the range of the surrounding rock loose circle after the surrounding rock of the roadway enters the rupture state.On this basis,the MATLAB software was used to analyze the sensitive factors affecting the range of the surrounding rock loose circle by using the control variable method,which was the compensation and improvement of the surrounding rock loose circle roadway support theory.The main conclusions of were as follows:①In the case of ideal elastoplasticity,it was impossible to determine the size of the loose ring range,and the size of the loose ring range could be determined by using the plastic potential theory to obtain the plastic strain and supplementing the condition that the radial strain was equal at the junction of the loose ring and the plastic zone;②The sensitive factors affecting the range of the loose circle were the mechanical parameters of the original rock and the stress of the original rock,while the supporting force and the cohesion of the surrounding rock in the loose circle had a weak influence on the range of the loose circle;③The cohesive force of the surrounding rock in the loose circle had a significant influence on the range of the loose circle within a limited range.Grouting reinforcement could effectively improve the cohesive force of the surrounding rock,and then reduce the range of the loose circle within a limited range.④It was theoretically proved that the influence of supporting force on the range of loose circle was small,which could be ignored under the existing supporting conditions.