基于钻孔应力监测的深部开采围岩应力演化及数值模拟研究

Research on surrounding rock stress evolution in deep mining and its numerical simulation based on borehole stress monitoring

随着矿山开采深度的增加,巷道受围岩应力的影响越发严重。巷道开挖后,引起附近围岩应力重新分布,其分布状况受地质条件和开采条件的影响,导致应力重分布越来越复杂。针对三山岛金矿深部地质情况,借助数值模拟软件对-870 m水平巷道进行整体稳定性分析,然后采用钻孔应力监测的方法对开挖岩层的内部应力场变化进行分析,确定围岩拉应力主要分布于斜联巷与脉外主运输巷交叉位置、脉外主运输巷与采联巷交叉位置和水仓等位置,最大为0.6 MPa;最大剪应力主要分布于斜联巷、脉外主运输巷拐弯处及东西走向巷道,最大为30 MPa。研究围岩应力分布的规律,为采场围岩稳定性评价及巷道围岩支护设计优化提供指导。

With the increase of mining depth,the influence of internal stress of surrounding rock on roadway becomes more and more serious.The excavation of roadway will cause the redistribution of internal stress of surrounding rock,which is influenced by geological and mining conditions.As a result,the redistribution is getting more and more complex.According to the geological conditions of the deep mining area of Sanshandao Gold Mine,the overall stability analysis of the-870 m horizontal roadway is carried out by numerical simulation software to determine the stress concentration position,then the internal stress field change of the excavated rock layer by the method of borehole stress monitoring is analyzed,determining that the tensile stress,with the maximum value being 0.6 MPa,is mainly distributed in the intersection of inclined roadways and outside-vein main haulage way,the intersection of outside-vein main haulage way and mining roadways,and the water sumps;the maximum shearing stress,30 MPa,is mainly distributed in the inclined roadways,the turnings of outside-vein main haulage way and EW-trending roadways.The study of surrounding rock stress distribution law provides guidance for the stability evaluation of surrounding pressure in stope and design optimization of surrounding rock support on roadway.