急倾斜俯伪斜上保护层保护范围的三维数值模拟

 针对急倾斜俯伪斜采煤法上保护层保护范围的划定难题，基于有限元法，结合保护层顶底板煤岩层的物理力学参数和地质特征，采用3D- 软件模拟急倾斜俯伪斜上保护层开采中被保护层的应力场及变形场的变化过程，得出保护层的保护效果，分析被保护层的最大主应力和变形随上保护层采煤工作面推进的变化规律；并根据保护层开采的应力卸压保护准则和变形保护准则，确定保护层沿倾向和走向的保护范围。结果表明，急倾斜俯伪斜采煤法上保护层沿倾向上、下边界的卸压角分别为84.9°和68.0°；沿走向的卸压角在倾向上呈非均匀分布，大小为38.3°～51.0°；同时，由现场考察方法与数值模拟方法所确定的急倾斜俯伪斜上保护层保护范围基本一致。因此，采用数值模拟方法来研究急倾斜俯伪斜上保护层的保护范围是可行的，且结果偏于安全。

THREE-DIMENSIONAL NUMERICAL SIMULATION FOR PROTECTION SCOPE OF STEEP INCLINED UPPER-PROTECTIVE LAYER OF PITCHING OBLIQUE MINING

Aimed at the problem of locating the protection scope of steep inclined upper-protective layer of pitching oblique mining(POM)，based on finite element method and the geological properties and the physico-mechanical parameters of roof and floor rock strata of protective layer，the changing processes of stress field and deformation field of protective layer after exploiting steep inclined upper-protective layer of POM are simulated by 3D-σ software. Then，the protecting effect of protective layer is gotten，while the changing laws of the maximum principal stress and deformation of protective layer along with the exploitation of upper-protective layer are analyzed. According to the protection rule of the deformation and stress-relief in exploiting protective layer，the inclination and strike protection scopes of protective layer are located. The results show that the upper and downside stress-relief angles along inclination of steep inclined upper-protective layer of POM are 84.9° and 68° ，respectively；The distribution of strike stress-relief angles along inclination of working face is uneven everywhere，and their values are 38.3°–51.0°. And the protection scopes of steep inclined upper-protective layer of POM located by the method of practical test and numerical simulation are basically consistent. The conclusion can be drawn that it is feasible to study the protection scope of steep inclined upper-protective layer of POM by using numerical simulation and its results are acceptable.