基于围岩等级的巷道锚网支护效果评价研究

Study on the Support Effect of Anchor Mesh in Roadway Based on Grades of Surrounding Rock

矿山巷道支护对于岩巷稳定性具有积极作用,针对巷道支护设计过于保守或考虑成本造成支护欠缺的普遍现象,提出了一种将围岩分级法等效内插至地质强度指标GSI中,利用Hoek-Brown强度准则和现场地质调查资料确定围岩力学参数的方法,根据现场施工方式模拟锚网支护结构,量化巷道锚网支护结构的安全性,建立了对应的支护效果评价经验公式,得到支护安全评价定量指标,结合现场监测数据检验了此方法的可行性。研究表明:巷道断面各点空间位移均随围岩质量弱化而增长,锚网支护体系在围岩等级4级左右已局部开始失效破坏;通过材料抗剪强度确定锚杆安全系数可有效快速评价支护效果及结构安全程度,从而实现按需支护设计。研究成果可为不同围岩等级的巷道锚网支护效果评价提供一种简便、有效的方法,可为现场巷道施工与设计提供参考。

Mine roadway support plays a positive role in the stability of rock roadway.In view of the common phenomenon that the roadway support design is too conservative or considering costs,resulting in a lack of support,a method was proposed,that was equivalently interpolating the surrounding rock classification method into the geological strength index GSI,so as to determine the mechanical parameters of surrounding rock by using Hoek-Brown strength criteria and on-site Geological survey data.The anchor mesh support support structure were determined according to the on-site construction method,the safety of anchor mesh support structure was quantified,and an empirical formula was established for evaluating the corresponding support effect.Finally,quantitative indicators for support safety evaluation were obtained,and the feasibility of this method was verified with on-site monitoring data.Research results show that,the spatial displacement of each point in the roadway cross-section increases with the weakening of the surrounding rock mass,and the anchor mesh system has locally started to fail at around grade 4of the surrounding rock mass.The factor of safety of anchor bolt determined by the shear strength of materials can effectively and quickly evaluate the support effect and structural safety degree,so as to realize the support design on demand.The research results can provide a simple and effective method for evaluating the support effect of anchor mesh in roadway with different grades of surrounding rock,and can provide a reference for on-site roadway construction and design.