条带开采垮落区注浆充填技术的理论研究

Theoretical study on the backfill grouting in caving area with strip mining

阐述了条带开采垮落区注浆充填技术的总体思路和基本原理,结合工业试验方案,应用PFC颗粒流程序进行了数值模拟试验,模拟了条带煤层采出、顶板垮落、注浆充填、充填体压实及上覆岩层下沉的整个动态发展过程;通过数值试验,揭示了条带垮落区充填体、煤柱与围岩三者之间相互作用的减沉力学机理,重点分析了垮落区充填体的承载作用、传载作用和对煤柱的侧限作用.研究结果表明,在此工业试验区域内,与条带开采相比,当充填量为19.5万m3时,条带开采垮落区注浆充填既可减小地面变形,提高煤柱稳定性,又可多采出煤炭24万m3.

The general framework and principles of grouting backfill in caving area with strip mining were introduced. The numerical simulation on the industrial experimental scheme was executed with the PFC particle flow code. The dynamic development process, which was from strip excavation, roof caving, grouting backfill and back- fill body compaction to the subsidence of overburden strata was simulated. With the survey of physical parameters, subsidence control mechanism was disclosed on the basis of the interaction of backfill, coal pillar and surrounding rock. The systematic analysis on the bearing capacity, load transfer of the backfill and its side confinement to the coal pillar were made. The result shows that, when the backfill volume is 195 000 m^3, the extraction volume can increase by 240 000 m^3 ; in this case, it can decrease ground deformation and stabilizes the pillar.