缓倾斜多层矿床条带法开采矿柱变形特征及开采强度模拟

Pillar Deformation Characteristics for Multilayer Gently-dipping Deposits by Strip Mining and Mining Intensity Simulation

为了实现高效安全开采,以上横山缓倾斜多层矿床为研究对象,采用数值模拟和物理相似模拟试验,分析了条带法开采矿柱的变形特征。结果表明：矿柱变形首先在端面尖点等软弱处产生,端面应变随回采进行不断积聚,变形呈不连续、非均匀分布和变化;当矿柱两侧均为采空区时,其下端面尖点和上端面低水平尖点均为高拉应变状态,应变量较上一时步增幅为2.95%~145.55%;当矿柱处于充填体上覆岩层内时,其中心应变均为变幅为5.67%~63.98%的压应变。矿柱的下层围岩或充填体的完整性和连续性是影响其稳定性和有效性的重要因素。考虑矿柱合理变形和采场的稳定性,确定最大不充填开采条带数为3条。工业性实践应用表明该开采强度能满足高效安全开采的要求。

Aiming at Shanghengshan multilayer deposits in gently dipping strata, the deformation characteristics of pillar in strip mining were analyzed based on the numerical simulation and physical simulation tests, so as to ensure effective and safe mining on mine. Results showed that as the panel mined, pillar deformation firstly occurred on failure points, such as the upper end of the pillar. The strain on upper end was increasingly accumulated with the progressing of stoping, resulting in the deformation distributed and varied discontinuously and unevenly. With both sides being mind-out area, the pillars were in a high strain state especially at the upper end and bottom end, with compressive strain increased by 2.95%- 145.55% than the previous step. As the orebody underneath the pillar was backfilled, the central strain of the pillar was the compressive strain with variation of 5.67% ~63.98%. Thus the integrity and continuity of backfills and surrounding rock underneath the pillar play an important role in keeping pillar＇s stability. Based on the consideration of pillar＇s deformation and stope＇s stability, it is suggested that maximally three strips be minded out without backfilling in the strip mining of such kind of deposit. On-site practice indicates such mining intensity can ensure the safety of the efficient mining.