基于安全系数和可靠度的极破碎矿体进路优化

Optimization of drift in extremely fractured ore-body based on safety coefficient and reliability analysis

基于极破碎矿体开采条件极其复杂、难以确定合理的进路断面参数等问题,建立下向进路薄板力学模型,得到进路承载层抗拉强度破坏判据。在此基础上运用安全系数法和可靠度理论研究进路宽度和高度对承载层拉应力的影响,并对这2种方法所得结果进行比较优化出最佳进路断面,进而开展ABAQUS数值模拟和现场试验验证断面优化的合理性。研究结果表明:进路宽度对承载层拉应力的影响较大,可采用"小宽度、大高度"的思路优化断面;安全系数和可靠度分析结果存在一定差异,且可靠度分析更合理;数值模拟结果与工业试验结果及可靠度分析结果较吻合,表明采用可靠度理论优化极破碎矿体进路断面是可行的,可实现极破碎矿体安全高效经济开采。

Considering that in the complicated mining conditions in extremely fractured ore-body, it is difficult to determine a reasonable cross section of drift, a mechanical thin plate model of downward drift and a failure criterion of tensile strength were studied when bearing layer collapsed was obtained. Then effects of drift width and height on tensile strength of bearing layer were studied by means of safety coefficient method and reliability analysis, and the best cross section of drift was gotten sequently by comparing results between these two methods. Moreover, ABAQUS numerical simulation and commercial test were conducted to validate the rationality of the most optimal cross section. The results show that the influence of drift width on tensile strength of bearing layer is more significant than that of drift height, and so an idea of small width and large height should be adopted to optimize cross section. There are some differences between safety coefficient and that of reliability analysis, and the latter is more reasonable. The numerical simulation and industrial test results are in good agreement with those obtained from reliability analysis, which indicates that reliability analysis is feasible in the optimization of drift in extremely fractured ore-body and can achieve safe, efficient and economical mining in extremely fractured ore body.