硬岩采场人工矿柱膨胀接顶机理与承载机制研究

A new type of artificial expansion pillar is being developed based on the expansion effect of static broken agent，which could solve roof-contacted effectively that traditional artificial pillar can’t realize. The expansion artificial pillar can effectively meet roof and actively support roof pressure，realizing the effective control of ground pressure. This project mainly studies the mechanical properties，roof-contacted mechanism，the yield stress support under high stress，resistance to impact load performance and carrying mechanism to roof of artificial expansion pillar. It could reveal its active support mechanism to study the relationship between inflation rate and pillar support and long-term load-bearing characteristics under different materials and ratios. Active local stress analysis model of stope roof is set up，exploring load-deformation law of pillar in the instability of roof，analyzing the effect of pillar supporting force to impact load of release energy capacity，optimizing the structural parameters of artificial pillar，using the pillar load capacity after peak strength, can adapt to the stress release and roof coordination deformation. By establishing the roof-pillar system synergy carrying mechanism，dynamic control technology can established under the effect of artificial expansion pillar and avoid pressure arch.

基于静态破碎剂的膨胀作用研发一种新型人工膨胀矿柱，解决了传统人工矿柱不能有效接顶的技术难题。该人工矿柱在回采过程中能够有效接顶，主动支撑顶板压力，实现采场地压的有效控制。本项目主要围绕人工膨胀矿柱的力学性能、膨胀接顶机理、高应力作用下人工膨胀矿柱的让压支护特性、抗冲击载荷性能及其对顶板围岩稳定性的承载机制开展科学研究，通过研究不同膨胀材料和配比条件下人工矿柱的膨胀率与矿柱支撑力关系和长期承载特性，揭示其主动支撑作用机理；建立采场顶板局部主动受力理论分析模型，探索采场顶板失稳过程中矿柱的承载-变形规律，分析矿柱初撑力对冲击荷载的释能效应，通过优化人工矿柱结构参数，利用矿柱峰后强度承载能力，以适应顶板的应力释放和协调变形；通过建立顶板-矿柱系统协同作用承载机制，研发人工膨胀矿柱和免压拱共同作用下的采场地压动态调控技术。

新型人工膨胀矿柱具有主动支撑、应变硬化承载性能，能够有效解决金属矿山采场地压大、留设原岩矿柱损失率高、构架传统人工矿柱接顶困难及被动承载难题。本项目主要围绕人工膨胀矿柱力学性能、接顶机理和承载机制开展科学研究。人工膨胀矿柱膨胀动力源的自由膨胀率为58.3%，强度高达90 MPa，随着膨胀动力源与限制体之间预留空间的减小或膨胀材料装填量的增加，其主动支撑力增加，且增加幅度加大；人工膨胀矿柱具有支护周期短（1-2 h）、主动支撑力大（1600 kN）、强度高（2800 kN）等优势。随着人工膨胀矿柱高径比的增大，其应变硬化承载区缩短或消失，极限承载力减小，膨胀矿柱更易失稳，其破坏区位于支撑结构中央，失效模式属于弯曲变形；人工膨胀矿柱能够使顶板压力得以适当释放后，稳定采场顶板处于一种塑性变形但又稳定的状态，实质性地实现采场顶板的“让压支护”；利用人工膨胀矿柱支护技术能够最大限度地发挥围岩的自稳能力，使顶板压力由原岩矿柱有效地转移至人工膨胀矿柱之上，在保证采场顶板安全的条件下，实现原岩矿柱回收、采场结构参数加大等技术。新型人工膨胀矿柱成本低、工艺简单，尤其快速、有效接顶特性填补了国内外的研究空白。人工膨胀矿柱接顶机理和承载机制的揭示，丰富了主动支撑的采场支护理论，为其进一步推广应用提供了理论依据。