含摩擦作用叠梁应力势函数对煤层顶板的破坏研究

Study on damage of coal seam roof by stress potential function of stacked beam containing frictional action

为了研究煤矿巷道顶板的破坏形式与机理,采用叠梁模型并引入应力势函数分析了叠梁模型中的应力分布状态;同时采用遍布水平节理与垂直节理对模型进行简化,结合摩尔-库伦强度准则分析了煤层顶板的破坏范围。结果表明:煤层顶板破坏的主要因素是由水平节理造成的离层以及由垂直节理造成的断裂;离层破坏域呈上陡下平的“类双曲线型”分布,断裂破坏域呈“拱形”分布;随着层间摩擦系数的增大,顶板离层破坏域高度和宽度显著降低,而弹性模量的增加对顶板破坏范围作用较小;随着间接顶的增大,顶板断裂高度逐渐降低、离层宽度逐渐提升。

In order to study the damage form and mechanism of coal mine roof,the stress distribution state in the stacked beam model was analyzed by using the stacked beam model and introducing the stress potential function;the model was simplified by using horizontal and vertical joints all over,and the damage range of coal seam roof was analyzed by combining Mohr-Coulomb strength criterion.The results show that the main factors of coal seam roof damage are layer separation caused by horizontal joints and fractures caused by vertical joints;the separation failure zone has a“hyperbolic-like”distribution with steep top and flat bottom,and the fracture damage zone has an“arch-shaped”distribution;with the increase of inter-bed friction coefficient with the increase of the interlayer friction coefficient,the height and width of the layer separation damage zone of the top plate decrease significantly,while the increase of the elastic modulus has less effect on the damage range of the top plate;meanwhile,with the increase of the indirect roof,the fracture height of the top plate gradually decreases and the layer separation width gradually increases.