某矿山断层附近采场地下开采对上覆岩层内井巷工程采动影响分析

    Study on the impact of a near-fault underground mining on sinking and drifting engineering in overlying rock strata

    • 摘要: 某矿山矿围岩稳固性好,矿体厚度较厚,矿体埋藏很深。为了实现该矿山185中段F3断层附近的矿体安全回采,同时确保采场顶板上覆岩层内井巷工程的安全稳定,依据断层附近的矿体赋存条件、顶底板围岩岩性特征、地质构造与上覆岩层结构特征,构建了地表与井下采场的三维数值计算模型,采用FLAC3D有限差分法来模拟地下开采在断层影响作用下对上覆岩层内井巷工程稳定性的影响分析,同时计算分析了地下矿体逐段开挖、逐段充填对保安矿柱及地表稳定性的影响。通过模拟计算结果表明:该岩层移动是一个自下而上传递的动态过程,断层附近矿体的开采通过采取设置10 m宽采场间柱和矿房之间采用“跳采”方式开挖后,大大缩短了采场空区的跨度,控制了断层附近的采场地压,并未引起采场顶板产生过多的塑性扰动区,上覆岩层产生的塑性扰动区范围非常有限,并未波及到采场顶板上部井巷工程,实现矿体顺利回采和上覆岩层内井巷工程的整体安全稳定。本文研究结果为深部矿体安全高效回采、采场地压管理和控制上覆岩层安全稳定提供了理论决策依据和技术指导。

       

      Abstract: A mine features with stable wall rock and thick, deep ore body. To ensure safe mining near the F3 fault in the 185 m horizon and shaft sinking and drifting in the overlying strata, a 3D numerical calculation model of surface and underground mining is constructed based on the occurrence of ore near the fault, rock lithology of the roof and floor surrounding rocks, geological structure, and the structure of overlying rock strata. FLAC3D measure is employed to simulate the impact of underground mining on the stability of sinking and driving in overlying rock layers. In addition, the impact of section by section excavation and backfilling on pillar safety and surface stability is calculated and analyzed. The results show that strata movement is a dynamic transfer from bottom to top. The near-fault mining is carried out by skip mining between 10 m wide pillars and mining rooms, which greatly shortens span of the goaf and controls the stope ground pressure near the fault without excessive plastic disturbance of the roof. Limited plastic disturbance in the overlying rock layer has no effect on the shaft engineering. The smooth mining and safe, stable shaft sinking and drifting are achieved. The study provides theoretical reference and technical guidance for safe and efficient deep mining, management of stope ground pressure, and safety and stability control of overlying rock strata.

       

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