为了探究煤矿底板采动破坏规律,以内蒙古不连沟煤矿F6106工作面为试验现场,分别从现场注水试验、底板岩层应变探测、理论预测计算三个方面对煤层底板采动破坏规律进行分析,现场底板探测得出底板岩层在工作面推到测点时出现第一次破坏,破坏深度约为185m,当工作面推过测点15~20m后,采空区底板岩层破坏深度出现二次加深现象,破坏深度加深1m,采后底板破坏最大深度为19.5m;Griffith破坏准则下的底板弹性理论预测结果得出底板最大破坏深度与煤层埋深H、工作面应力集中系数n、底板岩体的单轴抗拉强度Rt有关,底板最大破坏深度随着埋深、支承压力增大而增大,随底板岩体的单轴抗拉强度的增大而减小。工程实践表明,F6106工作面底板破坏深度现场探测结果与理论预测结果一致。
To research the damage law of coal mine floor, this paper analyzed the damage depth of coal mine floor respectively through the coal mine floor water injection test, rock strain detection and theoretical analysis. According to the field test, the first failure appeared in the floor as the working face advanced to the measuring point with a damage depth of about 18.5m, which deepened lm when the working face advanced 15-20m from the measuring point, and the maximum failure depth of floor was 19. 5m. Elastic theory calculated that maximum damage depth of mining floor is related with the seam depth H, the stress concentration factor n, the uniaxial tensile strength of rock Rt. The maximum failure depth of floor increases as the seam depth and support increases, and decreases as the uniaxial tensile strength of rock increases. The field test agreed with the theoretical prediction, indicating the theoretical calculation method can precisely predict the floor failure in Buliangou coal mine.