基于Hoek-Brown强度准则磷矿体开采稳定性分析

Stability analysis of phosphate rock mining based on Hoek-Brown strength criterion

磷矿是保障精细磷化工生产和粮食供应的物质基础,而地下缓倾斜磷矿体的开采一直是个难题.该文以湖北兴山后坪矿段磷矿层地下开采为研究背景,采用有限差分软件FLAC^(3D),基于Hoek-Brown强度准则,对磷矿层的开采过程进行了数值模拟.首先进行单轴压缩模拟试验,求得各岩体的单轴抗压强度、弹性模量和泊松比,模拟试验结果和室内试验结果基本一致.然后研究了磷矿层开采过程中采空区围岩的应力变化情况、上覆岩体的位移规律和矿柱屈服区分布情况,从而评价采空区的稳定性.最后,分析了在缓倾斜磷矿体中实施浅孔房柱法开采的可行性.

Phosphate rock is the material basis of fine phosphorus chemical production and grain supply.However,the mining of underground gently inclined phosphate rock is always a difficult problem.Based on the research background of underground mining of phosphate rock layer in Houping Section of Xingshan,Hubei Province,the finite difference software FLAC^(3D) and based on Hoek-Brown strength criterion were used to carry out numerical simulation of the mining process of phosphate rock layer.First,a uniaxial compression simulation test was carried out,and the uniaxial compressive strength,elastic modulus and Poisson's ratio of each rock mass were obtained.The simulation test results are basically consistent with the indoor test results.Then the stress changes of the surrounding rock in the goaf area,the displacement law of the overlying rock mass and the distribution of the yield area of the pillar in the process of mining the phosphate rock were studied,so as to evaluate the stability of the goaf.Finally,the feasibility of implementing shallow hole room and pillar mining in gently inclined phosphate ore bodies was analyzed.