顶板-煤柱系统长期承载力学特征及破坏失稳机理

顶板-煤柱系统长期承载破坏失稳诱发多种矿山灾害。课题从顶板与煤柱相互作用出发，围绕顶板-煤柱系统长期承载力学特征及破坏失稳机理，开展如下创新工作：（1）通过大尺寸岩-煤组合体长期承载试验模拟顶板-煤柱系统长期承载破坏失稳，阐释不同影响因素下组合体长期承载力学特性，从变形局部化、能量演化角度定量揭示其破坏失稳机理。（2）基于力学试验结果，建立岩-煤组合体承载力学模型，分析应力分布特征，明确岩-煤相互作用力学特征和机理；提出考虑界面效应的顶板-煤柱系统承载破坏准则，结合组合体破坏特征和数值计算结果，揭示顶板-煤柱系统破坏失稳力学机制。（3）基于现场实测与数值计算，获得煤柱分区破坏过程中煤柱和顶板应力、变形演化规律及其响应机制，建立基于煤柱和顶板变形、应力变化特征的顶板-煤柱系统破坏失稳评价指标体系。研究成果对完善顶板-煤柱系统长期承载破坏失稳机理及其灾变监测与防控等具有重要理论意义和工程价值。

Various mine disasters are induced by the instability and failure of roof-coal pillar composite system under under long-term bearing. In this research, long-term bearing mechanical characteristics and instability and failure mechanism of roof-coal pillar composite system are investigated from the interaction between roof and coal pillar. The follwing innovation works are carried out: (1) Long-term bearing failure and instability of roof-coal pillar composite system are simulated through the long-term bearing tests on large-scale rock-coal composite bodies, and long-term bearing mechanical characteristics of composite bodies under different conditions are studied. Their failure and instability mechanisms are quantificationally analyzed from views of deformation localization and energy evolution. (2) Based on the above test results, the bearing capacity model for rock-coal composite body is established and its stress distribution characteristics are anlyzed, and mechanical characteristics and mechanism of interactions between rock and coal are revealed. A failure criterion of roof-coal pillar system considering interface effect is proposed, and combining failure characteristics of composite bodies and numerical calculation results, the failure and instability mechanism of roof-coal pillar system is analyzed. (3) Based on field measurement and numerical calculation, evolution laws of stress and deformation of coal pillar and roof and response mechanism between them are investigated during thepartition failure process of coal pillar, and an evaluation index system for failure and instability of roof-coal pillar system based on variety characteristics of deformation and stress of coal pillar and roof. The research results have important theoretical significance and engineering value for improving the mechanism of long-term bearing failure and instability of roof-coal pillar composite system and monitoring, preventing and controling its catastrophe.