高承压水上底板采动岩体裂隙演化规律研究

Law of crack evolution in floor rock mass above high confined water

为深入研究深部高应力、高水压和强开采扰动复杂环境下的岩体破裂问题,按裂隙产生的位置和机理,将深部底板采动岩体裂隙分为剪切裂隙、层向裂隙和竖向张裂隙,利用力学知识分别演算获得了三种类型岩体裂隙的起裂准则。借助"钻孔双端封堵侧漏装置"对赵各庄煤矿1237工作面进行的底板破坏实测结果,研究了深部底板采动岩体的裂隙演化实测规律。结果表明:煤层采深越大,底板采动破坏深度越大;煤层开采过程中深部底板采动岩体的原生裂隙呈现先闭合后张开再闭合,新生裂隙起裂发育后逐渐闭合的演化规律;底板岩体破坏的初始位置和裂隙发育程度与岩层的岩性、受力等因素有关,验证了深部底板采动岩体裂隙起裂准则分析的准确性。

In order to deeply study the fracture of rock mass in deep mines with high stress,high water pressure and strong mining disturbance,cracks of floor rock mass after mining were classified into shear crack,layer crack and vertical opening crack according to their formation sites and mechanisms.Simultaneously,the initiation criterions of these three cracks were calculated by theoretical analysis. Through the monitoring results of failure floor at No.1237 working face in Zhaogezhuang Coal Mine by apparatus with double-ended resisting water and measuring leakage,the crack evolution law of deep floor was investigated.The results indicated that the deeper mining,the deeper failure floor; and the preexisting cracks of floor rock mass after mining presents the change process of close-open-close,and initiation-close to the new cracks of rock mass; the initial position and development of failure floor rock mass are associated with some factors such as rock lithology,stress,which validated the accuracy of crack initiation criterions to shear crack,layer crack and vertical opening crack presented in floor rock mass.