充填体下阶段水平矿柱回采顶板安全厚度及进路充填采矿法

为了安全回采松散矿碴及低强度充填体压覆下的阶段水平矿柱,采用古典杨森散体压力理论及矩形等厚薄板力学模型分析了留设顶板受载情况及安全厚度,并通过工程实例进行了验证。结果表明,当上中段破碎底部结构不予回采,下中段顶柱留设安全厚度时,可通过进路式充填采矿法实现水平矿柱的安全开采;其中,下中段顶柱高5 m,采高3.5 m,顶板安全厚度1.5 m,矿石回收率68%,贫化率3%,取得了较好的安全与经济效益平衡。

Roof safe thickness and drift cut-and-fill mining of horizontal stage pillar under overburden backfill materials

To realize the safe mining of horizontal stage pillar under loose ore particles and low- strength backfill materials, the roof loading and safe retentive thickness were analyzed following the classical Janssen granular pressure theory and mechanical model of rectangular uniform thickness plate, and onsite verification was carried out. The results showed that safe mining of horizontal pillar was premised on the preserve of upload fractured bottom and safe roof thickness, and the application of drift cut-and-fill mining. On this occasion, the roof of the lower stage was 5 m, where the mining thickness was 3.5 m, and the retentive roof was 1.5 m. Additionally, 68% ore recovery and 3% dilution were achieved, which was an preferable balance between safety and economy.