硬岩采场新型预应力膨胀支柱的研发及应用

针对硬岩采场原岩矿柱损失率高、传统人工矿柱无法有效接顶等难题，利用自主研制的膨胀材料水化反应后体积增大特性，研发一种新型预应力膨胀支柱;基于室内和现场工业试验，测定其膨胀力学性能和承载机制.试验结果表明，桶式膨胀装置(即膨胀支护动力源)在约束条件下，随着膨胀材料装填量的增加，其主动支撑力增加，且增幅逐渐加大;在全约束且满装膨胀材料的条件下，主动支撑力可达500kN.预应力膨胀支柱具有架设周期短(约4h)、主动支撑力大(约600kN)的优点;在房柱法残留矿柱回收过程中，预应力膨胀支柱呈现出应变硬化承载特性，原岩矿柱的负载能够成功地转移至预应力膨胀支柱之上;在确保顶板安全的条件下，试验采场经济效益增加170万元.

Development and Application of a New Pre-stressed Expandable Pillar in Hard Rock Stope

In order to solve the problems of high loss rate of natural pillars and the inability of traditional artificial pillars to effectively contact roof in hard rock stope， a new pre-stressed expandable pillar was developed by using the volume increase characteristic of the self-developed expandable material after hydration reaction. Based on the laboratory and field industrial tests， the mechanical properties and load bearing mechanism were determined. The test results showed that with the increase of the amount of expandable material in the barrel-type expandable device under constrained conditions， its active support stress increased with a gradually increased increment， and it could reach 500kN under the conditions of full constraint and fully filled with expandable material. The pre-stressed expandable pillar had the advantages of short construction period(about 4h) and large active support stress(about 600kN). When recovering residual pillars in the room-and-pillar mining， the pre-stressed expandable pillars showed strain-hardening bearing characteristics， and the load on natural pillars was successfully transferred to the artificial expandable pillars. Under the conditions of ensuring the stope safety， economic benefit of the test stope increased by 1，700，000 CNY.