地下采场破碎岩体稳定性评价与参数优化

Stability Evaluation and Parameter Optimization on the Fractured Rock Mass Around Underground Stope

以焦家金矿试验采场为工程依托,开展缓倾斜中厚破碎矿体采场稳定性分析.通过对焦家金矿-390 m中段试验采场的工程地质调查、矿岩力学性质试验,获得了表征矿山岩体工程质量的多种指标;应用岩石质量Q分级和RMR分级系统,对试验采场岩体稳定性进行评价分析;基于修正的Mathews稳定图法和临界跨度设计法,对采场暴露面尺寸和最大跨度进行优化.分析认为,当回采进路跨度小于8 m时即可保证采场的稳定性.将所得到的结果应用于现场工业试验,现场采用暴露面尺寸为7.5 m×15 m的进路进行回采,采用现场观测的手段进行回采过程的监测.结果表明,在回采过程中进路的顶板及围岩并未发生垮落及剥落现象,采场围岩稳定性良好.

The stope stability analysis of test stope in the gently inclined ore body with medium thickness was carried out in the Jiaojia Gold Mine,Shandong Province.By means of the engineering geologic investigation and rock mechanics experiments at the-390 m level,many mechanical indexes which reflect the quality of engineering rock mass were acquired.On the basis of the mass data analysis,applying of ＂Q＂and＂RMR＂rock mass quality classification,rock mass rating model was established.According to the rock mass rating model,together the revised Mathews stability graph and the critical span design method,maximum exposed surface size of stope and maximum span were obtained.Through this great amount of analysis,it will guarantee the stability of stope when the span of stoping drift is less than 8 m.The result was applied to the industry test,there the exposed surface size is designed as 7.5 m × 15 m,and the in-situ observation is used to monitor the mining process.The monitoring indicated that the caving and spalling of roof or sidewall do not occurred during the mining,and the stability of stoping drift is guaranteed.