大保当井田覆岩岩土比对开采沉陷的影响

Influence of Overburden Rock-soil Ratio on Mining Subsidence in Dabaodang Coal Field

以榆神矿区大保当井田2-2煤层覆岩为地质原型,基于区域地质条件和3个代表性钻孔构建了30个不同岩土比类型的数值模型,运用数值模拟实验的方法研究在地质条件和开采工艺相同的情况下,覆岩岩土比对开采沉陷的影响规律。结果表明:在100 m和200 m埋深水平下,随着岩土比的增大,下沉系数呈现较为明显的减小趋势,而在250 m埋深水平下,除各别点外(岩土比为2∶1时)也基本符合该规律;不同埋深水平条件下,随岩土比增大,下沉系数的减小幅度不同;基于数值模拟实验结果,超过80 m的厚土层具有降低下沉系数的效应。

Taking the overburden of 2-2 coal in Dabaodang Mine Field of Yushen Coal Mining Area as geological prototype,30 numerical models with different rock-soil ratio are established on the basis of regional geological occurrence conditions and 3 typical drillings.With the method of numerical simulation,the influence law of rock-soil ratio on the mining subsidence is researched under the same geological condition and mining technology.The results show that the subsidence coefficient could decrease with the increase of the rock-soil ratio in the 100m and 200m depth level; the overall trend of the subsidence coefficient could decrease when the rock-soil ratio increases（excluding the rock-soil ratio is 2： 1） in the 250 m depth level.In different depth level,the impact extent of the rock-soil ratio on subsidence coefficient is different.According to the results of numerical simulation,the super thick soil that is more than 80m could cut down the subsidence coefficient.