承压水上煤层开采后底板采动效应的数值模拟

Numerical simulation of mining effect of coal seam floor

在地下采掘活动中,预防底板突水事故的关键是煤层底板的隔水层能否阻止含水层的高压水涌入采掘空间。针对新登煤矿31061采煤工作面处于承压水上部存在突水风险的不确定性,依据31061采煤工作面的赋存状况和地质特点,分别建立隔水层厚度不同的区域数值计算模型。利用CDEM(Continuum-based Discrete Element Method)数值模拟软件对采煤工作面推进过程中煤层底板应力、变形情况、破坏区深度及突涌水情况进行模拟计算及对比分析。计算结果显示,煤层底板应力分布与工作面推进距离、采高及地板岩性等密切相关;当采煤工作面的隔水层厚度为8m时不能有效阻隔水压,煤层开采前需做好探水工作划分避让区域;另外模拟计算的底板破裂厚度值与规程计算值一致,为矿井的水害防治提供科学指导。

In the underground mining engineering, the key to the prevention of coal floor water inrush dis- aster is the coal floor aquifuge can prevent aquifer＇s high pressure water into the coal face. To 31061 coal face of XINDENG coal mine was above the floor with confined water has the existence of water burst risk uncertainty, for the occurrence state and geological characteristics of the 31061 coal face , the areal numerical calculation model of different thicknesses of floor aquifuges. The numerical simulation software CDEM （ Continuum - based Discrete Element Method）was used to simulate and analyze the floor stress, deformation conditions, the depth of the failur area and the sudden water inflow in the coal mining face. The paper show that the stress distribution of coal seam floor is closely related to the distance of working face, mining height and floor lithology; the thickness of the 8m thickness of the floor of the coal face can not effectively block the water pressure, and the water exploration work should be done before the coal mining;and the floor fracture depth value in the coal face is consistent with the calculated value of the regulation, which provided scientific guidance for coal mine safety.