双暴露面的阶段充填体孤柱需求强度模型及影响因素

阶段充填体孤柱侧壁均暴露、处于双轴受力状态,易发生剪切破坏.为合理确定其所需强度值,根据Terzaghi松散地压理论和滑楔体极限平衡理论,建立了孤柱需求强度数学计算模型,分析了需求强度的影响因素.结果表明:阶段充填体孤柱需求强度值与采场埋深和结构参数呈正相关,与充填体内摩擦角、充填体-围岩接触面摩擦系数和摩擦角呈负相关.该研究成果对指导矿山充填配比设计、防止地表塌陷和环境保护等具有现实意义.

Required Strength Model and Influence Factors of Stage Backfill-Pillar with Double Exposed Faces

Stage backfill-pillar with double exposed faces subjected to biaxial loads is prone to shear failure. In order to determine the required strength of backfill reasonably, Terzaghi theory on loosing earth pressure and limit equilibrium theory of sliding wedge were used to build a required strength model of stage backfill-pillar. Influencing factors for the required strength of stage backfill-pillar were analysed. The results show that stope depth and structure parameters have a positive effect on the required strength of stage backfill-pillar, while internal friction angle of backfill, and the coefficient of friction and angle between backfill and surrounding rock have a negative effect on it. The results are of great practical significance in guiding backfilling ratio, preventing ground subsidence and protecting the environment.