综合机械化固体充填采煤的充填体时间相关特性研究

Time-dependence of backfilling body in fully mechanized backfilling mining face

采用MTS 815.02电液伺服岩石力学试验系统对综合机械化固体充填采煤技术中的矸石与粉煤灰充填体的时间相关特性进行了测试,得到了3,7,13和20MPa压力条件下矸石与粉煤灰充填体时间相关特性曲线,应用流变的基本理论,选取PTh体作为矸石与粉煤灰充填体的流变模型,并建立了流变方程;根据矸石充填体时间相关性试验结果及试验矿井的相关数据,计算得出流变参数K1,K2,η,并得到综合机械化固体充填采煤工作面顶板的下沉量与时间的具体流变方程,根据流变方程得出了综合机械化固体充填采煤工作面顶板的下沉量与时间关系曲线,并得出当经历1 000h(约40d)之后,充填体流变进入稳定阶段,其变形量逐渐趋于定值,最大值约340mm.

Back filling with the solid waste during fully mechanized coal mining promotes effec- tive mining and provides protection for the environment. The MTS 815.02 mechanical testing system was used to determine the time dependent deformation of the back fill from a fully mechanized mining face. Time dependence was measured for pressures of 3 MPa, 7 MPa, 13 MPa, and 20 MPa. A PTh model was used as the rheologieal model for the waste with fly-ash back fill. The model terms K1, K2, and η were determined from the time dependent data and other experimental mine data. An equation predicting roof subsidence is presented. The roof subsidence is predicted to become stable after some time, with a maximum subsidence of 340 mm.