深部破碎易风化巷道失稳机制及治理分析

Failure mechanism and control analysis of fractured and easily weathered roadway in deep mining

针对深部破碎易风化岩体中巷道失稳破坏机制及支护加固方案开展研究。通过总结分析破碎易风化岩体中巷道失稳破坏模式,探讨巷道破坏失稳机制,提出现有支护方案的不足;通过理论分析得到适用于此类条件下巷道稳定性控制对策和支护结构参数;采用数值分析研究破碎岩体中巷道支护前后围岩位移及应力演化规律,验证优化支护方案的合理性。研究结果表明:破碎易风化巷道开挖,如不及时支护将导致岩体发育节理劣化、膨胀变形,产生拱形垮落及岩块滑塌;巷道拱顶采用Φ22 mm快硬水泥锚杆、侧帮采用Φ42 mm管缝锚杆且间排距1.0 m、拱顶及侧帮5 mm薄喷层+钢筋网为合理支护方案;数值分析围岩位移及应力演化规律验证支护方案的合理性,能保证巷道在掘进和回采时围岩稳定性,将变形及应力控制在合理范围内,满足矿山安全和正常生产需求。

The mechanism of roadway failure and support method in deep fractured and easily weathered rock mass were studied.The failure mechanism of roadway was analyzed by summarizing and analyzing the failure mode of roadway in fractured and easily weathered rock mass,and the deficiencies of existing support schemes were put forward.The stability control strategy and support structure parameters were obtained by theoretical analysis.Numerical analysis was carried out to study the displacement and stress evolution of surrounding rock before and after support in fractured rock mass.The results show that:without timely support when excavating in the broken and easily weathered rock mass will lead to both the development of rock joints and expansion deformation,thus arch caving and rock block collapse;tunnel vaultΦ22 mm rapid hardening cement,side help anchor theΦ42 mm seam pipe bolt and row spacing between 1.0 m and the arch and side help thin shotcrete layer+5 mm steel mesh for rational support plan;the numerical analysis of surrounding rock displacement and stress evolution law verifies the rationality of the support scheme,which can ensure the stability of surrounding rock during tunneling and mining,control the deformation and stress within a reasonable range,and meet the mine safety and normal production requirements.