老采空区重复采动条件下地质稳定性研究

针对闭坑30多年的大通煤矿四号井老采空区受小煤窑重复采动情况下的地质稳定性问题,利用钻孔取样及室内土工实验研究了松散层物理力学性质,采用瞬变电磁仪器对研究区50m和100m埋深视电阻率平面分布进行了现场探测,在此基础上对研究区地质稳定性进行了分区。研究结果表明,大通湿地单元第四系粘土层厚度稳定,透水性差,有效的阻隔了地表水通过入渗补给地下水;由于小煤窑的开采,研究区内中部和东部塌陷区活化,属于采空塌陷不稳定区,而其它区域相对比较稳定。研究结果为该区地质环境治理和生态系统重构提供了依据。

STUDY OF GEOLOGICAL STABILITY OF ABANDONED GOAF UNDER REPEAT MINING

For the geological stability issue with the old goafs of No.4 shaft of the Datong Coalmine that has closed for over 30 years under repeated mining subsidence conditions by small artisanal miners, this paper studied physical and mechanical properties of loose layers by borehole sampling and indoor geotechnical test, conducted a spot measurement of apparent resistivity planar distribution at 50m and 100m burial depths of the study area using transient electromagnetometer, on this basis, divided the study area in view of geological stability. The results indicated that the Quaternary clayey layer is stable in thickness in the Datong wetland unit, poor in water permeability, effectively preventing surface water from feeding groundwater by infiltration. As a result of small artisanal coal mining, depressions are activated in the middle and eastern parts of the study area, which belong to instable areas, and the rest is relatively stable. This research provides a basis for geological environment treatment and eco-system reconstruction in the area.