加固工程中准低级岩爆机理的塑性分析研究

Plastic Analysis and Research on the Quasi Lower Mechanism of Rock Burst in the Reinforcement Engineering

基于塑性理论的岩爆机理分析揭示柱表面混凝土块体崩裂时的塑性变形增量典型特征与工程实际相符,理论上揭示剪破面剪力超限是低级岩爆发生的机理。提出卸围压属塑性力学意义上的加载过程,这一加载过程在瞬间完成,是引起准岩爆的导因,利用Coulomb剪破条件及Tresca流动法则导出产生低级岩爆判据。根据工程典型数据计算的临界第三主压应力与岩爆其他强度判据计算的结果较接近,且具有计算方便、适于工程技术人员应用的特点。

Rock burst mechanism analysis based on plastic theory reveals that the typical characteristics of the plastic deformation increment when the concrete block on the pillar surface cracks is consistent with the engineering reality,which theoretically reveals that the over-limit shearing force on the shearing surface is the essential mechanism of lower rock burst. This paper proposes that unloading confining pressure is an instantaneous loading process in plastic mechanics. The loading process is completed in an instant,which causes quasi rock burst,the criterion for lower rock burst by means of Coulomb shearing condition and Tresca flow rule, and points out that the critical third principal compressive stress calculated according to typical engineering data is similar to other strength criteria of rock burst. It has a convenient calculation,application characteristics,which is suitable for engineering and technical people.