分阶段充填开采应力演化与地表减沉效果研究

Study on Stress Evolution and Surface Subsidence of Phased Filling and Mining Technology

为研究分阶段充填开采应力演化及地表沉陷特征,采用数值模拟和现场实测方法,对各阶段充填开采的采动应力与位移特点进行模拟和实测分析。结果表明:第1阶段开采时,煤柱为主要支护体,充填体为被动支护体,主要起到应力传递的作用,随顶板下沉开始逐渐承载,充填体与煤柱形成统一支护体,相互提高了支撑能力,该阶段顶板及地表仅出现轻微下沉;第2阶段开采时,其应力演化过程与第1阶段类似,煤柱最大垂直应力22 MPa,充填体最大垂直应力12.0 MPa,但顶板及地表下沉量幅度较大,第2阶段下沉占总下沉量的83.2%。实测结果与模拟结果规律性一致,相比垮落法开采,地表下沉减少了92%。

To study the characteristics of stress evolution and surface subsidence of filling mining technology, the numerical simulation and field measurement methods were applied for analysis. The results showed that in the first stage of mining, the coal pillar is the main support body, while the filling body is the passive support body, which mainly plays the role of stress transfer,as the roof subsidence begins to gradually bear the load, the filling body and the coal pillar form a unified support body, which improves the supporting capacity mutually, in this stage, the roof and the surface only slightly sink;during mining in stage 2, the stress evolution process is similar to that in stage 1, the maximum vertical stress of coal pillar is 22 MPa, and the maximum vertical stress of backfill is 12.0 MPa. However, the roof and surface subsidence is large, and the subsidence in stage 2 accounts for 83.2% of the total subsidence. The measured results are consistent with the simulated results. Compared with caving method,the surface subsidence is reduced by 92%.