为了研究矿柱底部严重剥落形成的上宽下窄型矿柱与早强胶结充填体的相互作用,进行了现场地质调查,选用石蜡模拟早强胶结充填体进行室内试验,同时进行数值模型的构建和试验模拟研究。试验结果表明:在加载过程中,破坏主要发生在矿岩中,石蜡充填体由于具有较强的变形能力,没有明显的破坏裂纹;矿岩中的裂纹主要沿矿岩和充填体接触面进行延展,直至延伸至临空面破坏;试样表壁的石蜡薄层表征显示在加载过程中,在试样表壁大的裂纹带附近伴随小裂纹产生。通过相关研究,厘清剥落型矿柱与早强充填体的相互作用机理及破坏规律,以便开展针对性的矿柱补强,确保充填采场安全稳定。
The spalling will take place continually at the bottom of pillar under the effect of static and dynamic load,and the pillar which is wide on the upside and narrow on the downside will come into being. Compared with the vertical pillar before spalling,its interaction with early strength cement filling body is more complex,while this is the key to ensure the stope stability during the early strength period of cement filling body. To study the interaction between the pillar being wide on the upside and narrow on the downside caused by the serious spalling at the bottom of pillar and the early strength cement filling body,the field geological investigation was carried out,then the laboratory tests were conducted by selecting paraffin to simulate the early strength cement filling body,at the same time,the construction of numerical model and experimental simulation research were carried out. The results showed that the damage mainly occurs in the ore-rock during the loading process. The paraffin filling body has no obvious damage cracks due to its stronger deformation capability. The cracks in the ore-rock mainly propagate along the contact surface of ore-rock and filling body,until reaching the free face damage. The paraffin thin layer characterization of the sample's surface wall indicates that the small cracks occur near the big crack zone on the sample's surface wall during the loading process. The interaction mechanism between spalling type pillar and early strength cement filling body and damage laws were clarified,so as to carry out the targeted pillar reinforcement and ensure the safety and stability of filling stope.