基于地压诱导致裂的高应力硬岩矿床优化回采数值模拟

摘要

采用离散元数值模拟分析软件3Dec,依据贵阳开阳磷矿深部硬岩矿床的工程实际情况建立三维数值模拟模型,对开阳磷矿深部硬岩矿床的3种不同开挖工况进行模拟计算,包括在矿体中开挖地压诱导致裂巷道及不同方向(水平向和竖向)、不同顺序(先上后下/先下后上)开挖后的巷道围岩体的位移和塑性区分布情况.结果表明:在矿体中开挖诱导致裂巷道时,巷道周边岩体塑性区和位移场随着暴露时间的延长而不断增大,矿岩朝着有利于破碎的趋势发展,即为掘进机的高效切割回采提供了有利条件;不同开挖方向对充分利用深部地压效果不同,竖向开挖比水平横向开挖可形成更大的位移场和塑性破坏区,地压致裂的效果更明显;先下后上式开挖比先上后下式开挖产生的临空面附近矿岩产生更大的变形量和破坏区,更能有效地利用深部地应力破岩.该研究对开阳磷矿深部高应力硬岩矿体非爆掘进机连续开采的采矿方法设计、充分利用地压破岩和合理确定开挖方式具有重要的意义.%The 3D numerical simulation model of deep hard-rock deposit in Kaiyang Phosphate Mine of Guiyang was established based on the practical engineering using 3 DEC numerical simulation software.The distribution characteristics of displacement fields and plastic zones of the orebody were simulated in three different excavation cases,including the case of excavation artificial inducted roadway in the orebody,the case of horizontal or vertical excavation direction and the case of the upward or downward excavation order.The simulation results indicate that the plastic zone and displacement field of surrounding rock around the inducted roadway are continuously increasing with the increase of the exposure time after digging an artificial inducted roadway in the orebody.Thus the raw rock ore becomes easier to be fragmented,which provides advantageous conditions for roadheader to cut high stress hard-rock.It is worthy noting that there is a large difference in effective utilization of deep ground pressure between horizontal and vertical excavation directions.The later can produce larger deformation and fracture zone than the former on the rock mass around the deduced roadway,which means that the later may utilize the high ground pressure more effectively to break hard-rock.And the obtained results also show that upward excavation order is more helpful for ground pressure to break rock than downward excavation order.