缓斜煤层长壁开采基岩老顶的不稳定性态  

Instability behaviors of main roof in gentle dipping seam longwall mining

作　　者：杨治林[1] 

机构地区：[1]西安科技大学理学院,陕西西安710054

出　　处：《岩土工程学报》2013年第S2期61-65,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(40572155);教育部科技发展中心基金项目(20096121110004)

摘　　要：应用初始后屈曲理论和尖点突变理论,探讨了缓斜煤层采场初次来压时基岩老顶破断后的不稳定性态。根据顶板结构的分岔集方程及分岔状态下的临界平衡条件,确定了基岩老顶的破断步距和断裂下沉,建立了岩块台阶下沉和回转失稳的判据。研究结果表明,顶板岩层破断后岩块处于稳定平衡或不稳定平衡状态:稳定平衡状态下,顶板的破断步距和断裂下沉之间存在着确定的关系;不稳定平衡状态下,岩块的台阶下沉与回转失稳必居其一;应用初始后屈曲理论和尖点突变理论,可根据缓斜煤层长壁工作面顶板结构的结构特征、岩体材料、以及上覆厚松散沙层等赋存状况,预测基岩老顶采场初次来压时可能出现的灾害形式。By applying the initial post-buckling theory and the cusp catastrophic model, the instability behaviors of gentle dipping key roof stratum during the first weighting are studied. By using the bifurcation set of key roof stratum and the critical equilibrium condition in a state of bifurcation state, the formulae for breaking convergence and breaking span of main roof are derived, and the criteria for step convergence and instability due to rotation after breaking of the main roof are established. It is pointed that the rock blocks are in a state of either stable equilibrium or unstable equilibrium after breaking of the main roof, that is, the breaking convergence has determinate relation with the breaking span in a state of stable equilibrium, and either step convergence or instability due to rotation for rock blocks may occur in a state of unstable equilibrium after breaking of the main roof. In accordance with the occurrence behaviors of roof structures, rock materials and thick unconsolidated layers above the roof, the integrated application of the initial post-buckling theory and the catastrophe theory can be adopted to determine catastrophic forms of the main roof structures during the first weighting.

关 键 词：缓斜煤层 基岩老顶 断裂下沉 台阶下沉 失稳 回转 

分 类 号：TD823.211[矿业工程—煤矿开采]