金川二矿区1250m以上贫矿开采影响研究

Influence Research on Low-grade Ore Mining above 1250 m Level in Jinchuan No.2 Mine Area

针对金川二矿区1250m以上贫矿回采影响问题,通过建立三维几何模型、网格划分、确定边界条件和初始应力场等,对14行回风井稳定性影响以及上覆岩体移动影响程度和影响范围进行了模拟,计算出1250m以上贫矿回采引起的岩体应力场和位移变化情况,并对回采影响进行了评估。结果表明,1250m以上贫矿开采对14行回风井围岩第一主应力和第三主应力的变化影响不大,最大值与最小值的差不超过5 MPa,井筒附近围岩的应力状态以压应力为主;1250m以上贫矿开采会对现有应力场产生影响,使得贫矿尖灭处以及底部与上盘岩体接触处出现较大的塑性区,进而产生一定的位移,开采影响范围为开采贫矿至四周超过20m的岩体。研究成果为后续贫矿开采提供了理论依据。

Aiming at influential problems of low-grade ore mining above 1250 mlevel in Jinchuan NO.2mine area,such as：the influence of No.14 ventilation shaft stability,and the influence on overlying rock movement,the simulation research was carried out through 3Dgeometry model establishment,mesh division,boundary condition settlement and primary stress field confirnation.Variations of the field stress and displacement caused by mining were calculated,further more,the mining influence was evaluated. The results shows that first principal stress and third principal stress around No.14 ventilation shaft are slightly changed by mining,and the difference between maximum value and minimum value is less than 5 MPa.The filed stress around the ventilation shaft mainly is compressive stress.The existing stress field around low-grade orebody would be impacted by mining,that is the locations where contact low-grade orebody ends and hanging wall,appear a larger plastic zone,and then form a certain displacement.The mining influence scope contains low-grade orebody and nearby 20 mrock around.This study provided theoretical reference for the low-grade orebody mining.