急斜煤层放顶煤开采中基本顶的溃屈破断分析  

Buckling failure of roof with top coal caving in steep seem

作　　者：张嘉凡[1] 石平五[2] 张慧梅[1] 

机构地区：[1]西安科技大学力学教研室 [2]西安科技大学能源学院

出　　处：《西安科技大学学报》2008年第2期392-396,共5页Journal of Xi’an University of Science and Technology

基　　金：国家自然科学基金资助项目(50274058);2005年高等学校博士点专项基金资助项目(20040704002)

摘　　要：针对急斜煤层水平分段放顶煤开采过程中基本顶破坏活动对工作面的影响,应用板裂介质力学计算模型,进一步研究结构分叉后平衡路径的演化途径;应用后屈曲能量准则建立平衡稳定模态幅值方程和溃屈极限长度方程。研究表明:分叉点附近的邻域与煤层赋存条件、岩体材料及结构几何特征有关;基本顶从初始屈曲到后屈曲的变形过程中,只有当正则因子改变正负号时,系统才会从一个状态跳到另一个状态,基本顶岩体结构的后屈曲是一个由分叉点后屈曲性态到极值点后屈曲性态的耦合过程;而由倾角确定的剖分因子始终控制着系统状态变量与载荷的对应关系,影响基本顶的稳定性。Based on the influence of the roof failure on work face with horizontal section top coal caving in steep seam and mechanical calculation model of sheet crack, the regions near furcation point and evolutions along length of the roof buckling failure in equilibrium biequilibrium path were investigated. First, the equation for limit all cases was established by using modality amplitude equation of equilibrium stability derived by post-buckling energy criterion. Then, the equations for modality amplitude and limit length of the roof buckling failure were established. It is shown that the stabile regions near bifurcation point have relations with the preservative condition of steep seem, the material of rock mass and the geometrical properties. In the process of roof deformation from initial buckling to post-buckling, only if canonical factor changes its plus-minus, does the system jump from one state to the other, the post-buckling of the structure rock mass is a coupling process from bifurcation point to extreme point post-buckling behavior. The ripping factor depending on steep singlevalued relation between the state variate and load, also influences the seem angle can determine stability of the roof.

关 键 词：水平分段放顶煤 板裂介质岩体 后屈曲 极限长度 溃屈破断 

分 类 号：TD325.3[矿业工程—矿井建设]