露天转地下开采隔层厚度安全分析

Safety Analysis of Interlayer Thickness from Open Pit to Underground Mining

针对露天转地下开采隔层厚度的确定问题,以湖北省某铜矿为例,优选鲁佩涅依特理论估算法得出隔层厚度的安全阈值为67.85 m.运用有限元数值分析软件Phase2D进行模拟,得出隔层厚度70 m时地下采场回采引起露天坑底的最大岩移达到10 cm,从而验证了理论估算值的合理性;确定了围岩的塑性变形区域,为地下采场的安全回采设计及支护提供了可靠的技术支撑.综合利用三维空区监测系统(CMS)和大型矿业软件Surpac,获取了露天坑和采空区可视化三维形态;对探测模型在敏感点进行剖切,将三维模型转化成二维剖面,实现隔层厚度的精确测量.研究表明,该矿山隔层厚度已至安全临界值,露天回采应该立即闭坑.

Aiming at the problem of determining the interlayer thickness from open pit to underground mining,we perform the numerical simulation using the software Phase^2D and taking a copper mine in Hubei province as the case study,the safety threshold of the thickness is 67.85 m according to the Lupeinie theory.When the interlayer thickness is 70 m,the maximum rock movement of the bottom of the open pit may reach 10 cm,well verified the theoretical estimation.In addition,the plastic deformation area is determined,which provides a reliable technique support for the design of underground mining.Combined with Cavity Monitoring System（CMS） and large-scale numerical software Surpac,the 3-D visual configration of open pit and goaf is obtained.This 3-D model is then transformed into 2-D profile.By doing so,the thickness of interlayer can be accurately determined.According to our study,the thickness of interlayer in this mine has reached the safety critical value,showing that pit should be immediately closed.