基于Mathews稳定图表法的大红山铜矿采场顶板稳定性分级标准研究OA

To address the challenges of roof stability control in the deep mining of Dahongshan Copper Mine,a stope roof stability classification model was established based on the theoretical framework of the Mathews Stability Graph Method.This model systematically integrates geological parameters of the rock mass,characteristics of the in-situ stress field,and historical caving case data from the western mining section of the mine(including the 285/385 and 180/-20 middle levels)By quantifying rock mass quality indices,stress conditions(rock stress coefficient A),and the spatial relationships of structural planes(joint orientation coefficient B=0.5),and incorporating stope geometric characteristics(hydraulic radius to characterize exposed surface morphology),a nonlinear classification criterion was established.Zonal thresholds were determined:for the main mining section,the stable zone(exposed area≤863 m2),critical zone(exposed area 863-1 623 m2),and unstable zone(exposed area＞1 623 m2);for the western mining section,the corresponding thresholds were 811m2 and 1 067 m2.The reliability of the model was verified using 52 stope cases.The results indicate that the stope is significantly affected by its large exposed area,leading to a substantial increase in caving risk.Therefore,it is proposed that the stope planning for the 185 level should strictly limit the exposed area as an engineering countermeasure.