Stability analysis of underground mine hard rock pillars via combination of finite difference methods, neural networks, and Monte Carlo simulation techniques
Stability analysis of underground mine hard rock pillars via combination of finite difference methods, neural networks, and Monte Carlo simulation techniques
复制标题
结合有限差分法、神经网络和蒙特卡罗模拟技术进行地下矿山硬岩柱稳定性分析
DOI：
10.1016/j.undsp.2020.05.005
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发表时间：
2021-08-01
影响因子：
6.4
通讯作者：
Li, Xibing
中科院分区：
文献类型：
--
作者：
Li, Chuanqi;Zhou, Jian;Li, Xibing
支柱稳定性始终使用安全系数 (SF) 进行评估，安全系数定义为支柱强度与支柱应力之比。然而，大多数研究人员使用矿柱形状比（w/h）、完整岩体的单轴抗压强度（UCS）和矿柱深度（H）来估计矿柱应力。在这项研究中，硬岩柱的地质强度指数（GSI）被认为是用于预测目的的新变量。该指数是通过结合数值模拟软件（即 FLAC3D）和反向传播神经网络（BPNN）开发的。基于确定性方法、敏感性分析和蒙特卡罗模拟（MCS）三种方法进行了硬岩柱稳定性分析。提出了一个新的公式来根据预测应力估计 SF 值，并考虑确定性方法中的 GSI 变量。敏感性分析表明，影响SF的变量从高到低依次为UCS、GSI、w/h、H。本研究主要采用GSI和MCS技术对矿柱稳定性进行分析。 MCS结果表明，GSI也是支柱稳定性的主要因素，并且对弱支柱的影响大于对强支柱的影响。此外，当 GSI 和 UCS 都减小时，支柱更有可能不稳定。这项研究为改进稳定支柱的设计提供了一些参考和程序，考虑到GSI作为一个重要因素。
Pillar stability is always evaluated using the safety factor (SF), which is defined as the ratio of pillar strength to pillar stress. However, most researchers have estimated pillar stress using the pillar shape ratio (w/h), uniaxial compressive strength (UCS) of the intact rock mass, and pillar depth (H). In this study, the geological strength index (GSI) of hard rock pillars was considered as a new variable for predictive purposes. This index was developed by combining numerical simulation software (i.e., FLAC3D) and a backpropagation neural network (BPNN). A hard rock pillar stability analysis, based on three methods including deterministic method, sensitivity analysis, and Monte Carlo simulation (MCS), was performed. A new formula was proposed to estimate the SF values based on the predicted stress, considering the GSI variable in the deterministic method. The sensitivity analysis indicated that the variables impacting the SF from high to low are UCS, GSI, w/h, and H. In this study, pillar stability was analyzed mainly using the GSI and MCS techniques. The MCS results revealed that the GSI is also a major factor in pillar stability and has a greater effect on weak pillars than on strong ones. Furthermore, a pillar is more likely to be unstable when both the GSI and the UCS are decreased. This study provides several references and procedures for improving the design of stable pillars considering the GSI as an important factor.