石灰岩坚硬顶板弱化与巷道支护研究

Research on weakening of limestone hard roof and roadway support

针对店坪煤矿石灰岩顶板回采巷道顶板锚网支护施工困难和回采期间采空区悬顶面积大的问题,通过地质力学测试,工程经验借鉴,数值模拟分析,在巷道掘进期间,提出在保障巷道围岩稳定的条件下降低顶板支护密度的支护方案,一方面提高巷道掘进速度,满足矿井生产衔接需求;另一方面降低巷道支护成本,增加企业效益。在回采期间,提出合理的顶板预裂爆破放顶方案,减小采空区悬顶面积和回采巷道超前段应力集中,保障回采过程中工作面及两巷围岩稳定,现场跟踪监测分析表明,围岩动态稳定。

In view of the difficulties in the construction of bolt mesh support of limestone roof and the large hanging roof area in the goaf during mining in Dianping coal mine,through the geomechanical test,engineering analogy and numerical simulation analysis,the scheme of reducing the roof support density under the condition of ensuring the stability of surrounding rock of roadway is put forward,which can not only improve the tunneling speed of roadway,but also reduce the cost of roadway support and increase enterprise benefits.During the mining period,reasonable roof presplitting blasting caving scheme is adopted to reduce the hanging roof area in goaf and the stress concentration in the advance support section of the roadway,so as to ensure the stability of the surrounding rock of the working face and the mining roadways during the mining process.The field monitoring analysis shows that the surrounding rock is stable.