不同压实矸石充填体置换``三下''煤柱的岩层移动规律

STRATA MOVEMENT WHERE COAL-PILLAR UNDER WATER, BUILDING OR RAILWAY IS REPLACED BY GANGUE BACKFILLS OF DIFFERENT COMPACTNESS

  • 摘要: 为了分析不同压实矸石的充填体置换``三下''煤柱所引起的岩层移动及稳定性等问题,采用弹簧原理和弹塑性理论分析了上覆岩层和矸石充填支撑体的压缩机理, 并推导了矸石充填体的初期压缩量; 根据充填体的压实原理、岩层力学及相关理论, 推导了不同矸石充填体压实度所对应的压缩值及等价采高的解析式; 结合工程实例, 采用理论计算和数值模拟方法分析了不同矸石充填体置换煤柱所对应的上覆岩层移动规律. 结果表明, 随着充填体压实度的减小, 二次岩层移动所引起的顶板下沉值和等价采高都是不断增大的, 而当孔隙比达到0.55左右, 所得到的等价采高H_e增长速度更加灵敏, 并且最大侧向位移增加趋势明显加快.

     

    Abstract: In order to study strata movement and stability where coal-pillar under water, building or railway is replaced by gangue backfills of different compactness, spring principle and elastic-plastic theory are used to analyze the compression mechanism of gangue backfills assupporting bodies, and related formula for the early stage compressionis obtained. The compression value and the equivalent miningheight for different compactness is obtained based on compaction principle ofgangue backfills and rock mechanics. In a engineering example, thetheoretical calculation and the numericalsimulation are used to analyze strata movement for gangue backfills of different compactness. It is shown that the roof subsidence andthe equivalent mining height of quadratic strata movement steadilyincrease with the decrease of compactness degree of gangue backfills.When the void ratio is about 0.55, the increment speed of equivalent miningheight becomes very sensitive and the rising tendency of the maximum sidedisplacement become marked.

     

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