“三硬”煤层开采覆岩活动规律相似材料试验研究  

Similar material experimental study on the mining of “the three-hard” featured coal seam o the underlying strata migration

作　　者：王俊光[1] 梁冰[1] 田蜜[1] 

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《安全与环境学报》2014年第1期29-32,共4页Journal of Safety and Environment

基　　金：国家自然科学基金项目(51178457);教育部博士点基金项目(20122121120004)

摘　　要：为研究"三硬"煤层开采覆岩活动规律及采动支撑压力变化,以忻州窑矿8935工作面为研究对象,通过开展相似材料模拟试验,分析"三硬"煤层开采覆岩破坏特征及应力变化规律,得出上覆岩层损伤演化规律。结果表明:顶板垮落规律明显,初次垮落具有突发性,无明显征兆,且初次垮落步距较长,周期来压规律明显;开采过程中顶板、底板、煤层支撑压力动态变化,且应力集中系数最大值出现在煤层中,极易出现煤层突出。根据顶、底板应力变化规律划分支撑压力影响区域。The paper intends to take the working face of No. 8935 Xinzhou Coal Mine as a case study sample to make an exploration of the moving activities of the overlying strata of the mined ＂three hard＂ coal-seam with the corresponding changes of the supporting pressure caused by the mining practice. Failure characteristics and stress change laws of overlying strata of the mined ＂three hard＂ coal seam are analyzed through similar material simulation experiment, and the evolution of damages of the overlying strata is provided. The results show that： Compared with obvious roof caving, the initial caving is sudden with no obvious signs and has longer intervals and obvious cy- cle weighting phenomenon; During the excavation, the supporting pressure of roof, floor and coal seam are dynamically changed with the stress concentration factor of roof varies from 1.4 to 2.5, coal seams 1.2 to 2.0 and floor 2.2 to 4.4 respectively. The stress con- centration factor reached the maximum in the coal seam which is very vulnerable to the extrusion. The supporting pressure can be divided into four influence areas according to the stress change laws of the roof and floor, including non-＇,：fffected area, stress increasing area, stress decreasing or recovery area and stable stress area. The seventh floor of mined roof strata fluctuates its damage without severe ones. While the 8 11 floors of roof strata in mining area are severely dam- aged. With the proceeding of excavation, the supporting pressure continuously increases to the limit where the saved energy will be re- leased instantly and the strong impact will happen in rock strata. Ac- cording to the regression analysis of rock damage evolution data, the damage basically remains unchanged at early excavation and presents slow increase which is followed by gradually exponential growth and the loss of bearing capacity in the rock strata. Therefore, strong im- pact can easily be caused during the excavation of the coal in the overlying strata of the said coal seam which tends to

关 键 词：安全工程 三硬 覆岩 相似材料 应力集中系数 损伤演化 

分 类 号：TD325[矿业工程—矿井建设]