基于弹性薄板理论的采场顶板破断特征分析

摘要

In view of the particular spatial structures and deformation shape induced by overlying strata during the coal exploitation process,roof mechanical model with three kinds of boundary support conditions of four edges clamped,two edges clamped and two edges simple supported,and four edges simple supported was built up by using the theory of small deflection of elastic thin plate. The analytic expression of roof deflection,bending moment and stress before and after fracturing of basic roof was obtained through theoretical calculation. Furthermore,the theoretical analysis on the roof breaking mechanism and be-havior characteristics of roof fracture revealed the mechanical nature of stope roof with horizontal "O-X" shape fracture. The distribution rule and evolutionary characteristics of stress field in stope roof were studied by using three-dimensional numerical simulation software FLAC3D ,where the simulation results are consistent with the theoretical analysis.%针对煤层开采过程中采场覆岩形成的特定空间结构和变形破断形态，运用弹性薄板小挠度理论构建四边固支、两边固支两边简支和四边简支3种支承边界条件下的顶板力学模型，通过理论计算得出了基本顶断裂前后的挠度、弯矩和应力解析表达式，并从理论层面分析了顶板破断的内在机理与显现特征，揭示了采场顶板横“O-X”破断的力学本质。采用三维数值模拟软件FLAC3D 系统分析了顶板应力场的演化特征和分布规律，模拟结果与理论分析较为吻合。