基于充填置换开采技术的承压含水层底板裂隙带演化规律研究

Study on the Evolution Law of Bottom Plate Fissure Zone of Pressurized Aquifer Based on Filling and Replacement Mining Technology

煤层开采引起的扰动会导致底板岩层移动和被破坏,底板采动裂隙可能扩展至承压含水层,从而引发突水灾害。为探究承压含水层底板裂隙带演化规律,在承压含水层上方采用条带开采和充填体置换开采分别计算底板的破坏深度,并将其简化为半平面物体的力学模型。结果表明,条带工作面宽度和煤柱宽度对底板破坏深度有重要影响,宽度越宽,破坏深度越深。根据参数研究结果,回采工作面和留设煤柱宽度20 m能够防止突水事故的发生,置换遗留煤柱后,底板岩层破坏面积增大,但最大破坏深度保持不变。

The disturbance caused by coal seam mining leads to the movement and destruction of the rock layer of the bottom plate,and the fissure of the bottom plate mining may be extended to the pressurized aquifer,thus triggering the water-surge disaster.In order to investigate the evolution law of bottom plate fissure zone in the pressurized aquifer,strip mining and fill replacement mining are used above the pressurized aquifer to calculate the damage depth of the bottom plate and simplify it to the mechanical model of a half-plane object.The results show that the width of strip face and the width of coal pillar have an important influence on the damage depth of bottom plate,and the wider the width,the deeper the damage depth.According to the results of parameter study,the width of strip working face and coal pillar left 20 m can prevent the occurrence of water-surge accident,and after replacing the leftover coal pillar,the damage area of the floor rock body increases,but the maximum damage depth remains unchanged.