提出基于动态强度折减法分析矿柱渐进失稳演变的方法，揭示矿柱渐进失稳演变规律。通过理论分析，给出平面应变模型的屈服接近度指标Y，确定矿柱破损区域。利用某大型金矿工程实例，构建FLAC矿柱失稳数值模型。随着循环动态折减计算，破损区首先出现在矿柱4个边角部位，逐渐向底部中心区域扩展，直至贯通整个矿柱。破损区演变可分为稳定、扩展、突变等3个过程；随着迭代计算步长增加，破损单元数量由缓慢增加、稳定增加到急剧扩展。与整体强度折减法相比，该方法准确揭示矿柱渐进破坏机理，客观描述矿柱渐进失稳演变趋势和变形破坏程度，克服容易人为夸大破损区、产生不正常破损区的缺憾。现场位移监测结果验证了该方法分析结果的正确性。动态强度折减法为研究矿柱失稳机理和安全评价提供了一种新的有效方法。%In order to reveal gradual evolution law of pillar, dynamic strength reduction calculation methods was proposed for analyzing pillar progressive failure process. Through theoretical analysis, yield proximity indicatorsYin plane strain model was used to determine the damaged region of pillar. The pillar instability numerical model was constructed with FLAC based on a large-scale mining. With the dynamic cycle reduction calculation, pillar damage appeared from the corners firstly, and then gradually to the bottom center and evolved to breakthrough. The evolution of damaged area can be divided into three processes including stabling, expanding and mutating. As the iterative step length increases, the number of damaged cells increases from slowly to stably and then expands rapidly. Compared with the overall strength reduction, the method accurately reveals the pillar progressive failure mechanism and objectively describes the evolution trend of gradual evolution and pillar deformation, which overcomes the shortcomings of artificially inflating damaged area and producing abnormal damaged area. The correctness of the analytical result is verified by in-site displacement monitoring result. Dynamic strength reduction method provides effective way for research on pillar failure mechanism and safety evaluation.
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