新城金矿滕家矿区深部巷道围岩破坏与数值分析

Surrounding Rock Failure and Numerical Analysis of Deep Roadway in Tengjia Mining Zone of Xincheng Gold Mine

针对新城金矿滕家矿区深部巷道围岩进行现场工程地质调查、岩石力学实验,分别应用RMR、Q和GSI方法对巷道围岩进行岩体质量分级,确定其围岩体质量等级为Ⅲ级,岩体质量差～一般。以岩体质量分级为基础,应用Hoek-brown准则和经验公式估算岩体力学参数。应用弹塑性力学解析巷道围岩塑性区破坏范围,并以此为基础应用Phase2对巷道围岩稳定性进行分析。结果表明:巷道顶板塑性破坏范围为0.598 m,两帮塑性破坏范围分别为0.84m和0.695 m;巷道顶板位移为7.2 mm,两帮位移分别为7.6 mm和6.8 mm;从巷道围岩应力分析可以看出,深部巷道开挖产生的应力集中超过岩体强度,由此判断深部巷道围岩破坏主要是开挖扰动应力作用在节理化岩体上致使巷道围岩失稳破坏,本研究结果对该矿深部巷道围岩支护提供依据。

Based on the field engineering geological survey and rock mechanics experiment of deep roadway surrounding rock in Tengjia mining area of Xincheng Gold Mine, the rock mass quality of roadway surrounding rock is classified as Grade Ⅲ, poor or general level, by RMR, Q and GSI methods respectively. Based on rock mass quality classification, Hoek-brown criterion and empirical formula are used to estimate rock mass mechanical parameters. Elastic-plastic mechanics is adopted to analyze the failure range of plastic zone of roadway surrounding rock, and Phase 2 is used to analyze the stability of surrounding rock of roadway. The results show that the plastic failure range of roadway roof is 0.598 m, the plastic failure range of two sides is 0.84 m and 0.695 m respectively. The displacement of roadway roof is 7.2 mm, and the displacement of two sides is 7.6 mm and 6.8 mm, respectively. From the stress analysis of roadway surrounding rock, it can be seen that the stress concentration produced by deep roadway excavation exceeds the strength of rock mass. So, it can be judged that the damage of deep roadway surrounding rock is mainly caused by stress of excavation disturbance on jointed rock mass, resulting in the failure and destroy of roadway surrounding rock. This study provides a basis for supporting surrounding rock of deep roadway.