煤矿井下留设煤柱蠕变规律

Creep law of preserved pillar in the pit of coal mine

为研究复杂应力状态下条带煤柱的长期稳定性及其变化规律,采用理论分析和数值模拟的方法,推导了井下留设煤柱的蠕变模型,分析了该模型具有应变随时间变化逐渐增大而后又趋于稳定的非线性特征,同时试验得出的蠕变曲线也验证了模型的衰减蠕变过程.FLAC3D模拟研究结果表明,七台河90#条带煤柱的蠕变类型为衰减蠕变,煤柱在开采结束的第三年进入稳定蠕变阶段,这与现场地表破坏程度的考察及矿方对地表下沉的监测结果相符合.研究对胜利煤矿一采区的上覆岩层和地表建筑物起到了很好的保护作用.

In order to study the long-term stability of coal pillar under complicated stress state and by using the theoretical analysis and numerical simulation method, this paper derived the protection coal pillar creep model, and analyzed the nonlinear characteristic of model that the stain increases with time gradually and then tends to stable. At the same time, the creep curves of experiments validate the attenuation creep process of the model. FLAC3D simulation results indicate that, the creep type of ShengLi coal mine 90# coal pillar is attenuation creep, coal pillar enters the stable creep stage in the third year at the end of mining, which conforms to the surface damage of investigation and the monitoring results of surface subsidence. The research results preliminary break through the understanding of creep model at different stages of coal pillar, and it plays a very good role in protection for the overburden and surface buildings of ShengLi coal mine first mining area.