某石膏矿床深部开采稳定性分析

Stability Analysis on Deep Mining in a Gypsum Deposit

某石膏矿采用房柱法进行回采,开采范围内已经形成大面积采空区,且矿区范围内有村庄,人口稠密。为对-400 m以下深部资源进行科学开采并保障地表建(构)筑物安全,采用数值模拟的方法分析开采对岩体的稳定性及地表变形的影响。结果表明:-400 m以下矿体分层开采后,岩体的最大变形和竖直位移都出现在顶板位置,整体变形均偏小,下沉或底鼓现象并不明显;矿柱部位出现区域压应力集中,最大达26.38 MPa,矿房边墙所受拉应力较小,不超过2 MPa,整体无较大应力集中区域和塑性贯通区;地表沉陷最大位移为2.72 mm,水平变形最大值为0.0035 mm/m,倾斜率最大值为9.1×10^(-3)mm/m,曲率最大值为6.74×10^(-5)mm/m^(2),各指标结果表明-400 m以下矿体分层开采整体稳定,对地表建(构)筑物的影响很小。

A gypsum mine adopts room-and-pillar method for mining.Large mined-out area has formed within the mining area,and there are villages within the mining area with dense population.In order to scientifically exploit deep resources below-400 m and ensure the safety of surface buildings,numerical simulation method was used to analyze the influence of mining on the stability of rock mass and surface deformation.The results show that after stratified mining of orebody below-400 m,the maximum deformation and vertical displacement of rock mass appear in the roof position,the overall deformation is small,and the subsidence or floor heave phenomenon is not obvious.There is a regional compressive stress concentration at the pillar,and the maximum is 26.38 MPa.The tensile stress of the side wall of the mine room is small,no less than 2 MPa,and there is no large stress concentration area and plastic breakthrough area.The maximum displacement of surface subsidence is 2.72 mm,the maximum horizontal deformation is 0.0035 mm/m,the maximum inclination rate is 9.1×10^(-3)mm/m,and the maximum curvature is 6.74×10^(-5)mm/m^(2).The results of each index show that the stratified mining of orebody below-400 m is overall stable,and has little effect on surface buildings and structures.