露天矿山开采对下部既有巷道稳定性的影响分析

Study of the Influence of Open-Pit Mining on the Stability of Existing Tunnel under the Mine

摘要: 为了研究露天矿山开采对下部既有巷道的影响程度，确定露天矿山拟开采的深度，本文依托重庆某建筑石料用灰岩露天矿山拟开采过程，采用三维有限元分析方法，对露天矿山开采引起的下部不同高程的既有巷道围岩位移、应力及塑形发展过程进行了分析。当开采高程为+470 m时，+439、+425高程的巷道均较稳定；当开采高程低于+470 m时，矿山开采对+439、+425高程的巷道稳定性有较大影响，据此确定了比较合理的露天矿山开采深度64 m (+470 m)。

Abstract: In order to study the influence of open-pit mining on the existing tunnel below and determine the proposed mining depth of open-pit mine, this paper, based on the proposed mining process of a limestone open pit mine for construction stone in Chongqing, use three-dimensional finite element analysis method to analyze displacement, stress and shaping of the surrounding rock of existing tunnel at different elevations caused by open pit mining. When the mining elevation is +470 m, the tunnel at +439 m and +425 m is stable. When the mining elevation is lower than +470 m, it has a great influence on the stability of tunnel at +439 m and +425 m. Therefore, a reasonable mining depth of 64 m (+470 m) is determined.