以海石湾矿山地下开采为背景,借助基于连续介质力学的离散元方法——CDEM数值模拟计算方法,对山区下煤层开采过程中不同采动影响模式下覆岩的移动和破坏进行了模拟分析,并结合相似模拟试验与现场岩移监测所得结果,得到了顺坡推动式采动影响模式及逆坡牵引式采动影响模式下,覆岩的移动和破坏形式,并从数值分析和实际观测上验证了高顺坡开采转低逆坡开采时覆岩悬臂梁结构的存在,解释了坡底局部隆起的现象。研究表明,在相同地质条件下,顺坡开采坡顶易发生张拉及剪切破坏,坡底有剪切蠕滑的可能,因此,较逆坡开采对边坡稳定性影响更大。所以在实际生产中宜将上工业广场建于低矮的坡体较完整的逆坡上。
In this study, the movement and failure modes of overlying strata at Haishiwan mine are analyzed for different mining modes at mountainous field by using a numerical approach named continuum-based discrete element method(CDEM). In combination with the results of physical modeling experiment and the surface displacement data from field monitoring, the movement and failure modes of overlying strata caused by the ‘push mode' along slope and the ‘traction' mode along inverse slope are obtained. Besides, the upheaval phenomenon of slope basis induced by cantilever structure effect is confirmed through numerical analysis and in-situ observation. The study shows that under the same geological conditions, tension and shear failures are prone to appear along the slope crest, but shear creep deformation is prone to arise at the slope foot. As a result, mining along a slope has a greater impact on the slope stability than that along inverse slope. Therefore, an industrial ground is recommended to be built on the low inverse slope with some degrees of intact strata.