Study on electrical property variation law of overburden strata above seam under mining influences

In order to accurately determine the mining deformation and failure scope of the overburden strata above seam and better understand the apparent resistivity variation and failure development features of the overburden strata under the influences of the seam mining,in combination with the mechanics properties of the surrounding rock,lithology,mining method and other factors,a comprehensive analysis was conducted. The overburden strat a were divided into three different electric conductivity sections ,including a plastic failure section,e lastic-plastic transition section and elastic section. T he geoelectric models of the overburden strata with normal electric property dynamic variation and existed water flow crack zone under the influences 0 f the seam mining were established individually and a forward simulation study was conducted on the model. The results showed that affected by the mi ning,the apparent resistivity of the overburden strata was varied obviously and the apparent resistivity abnormal zone would be displaced with the forwa rd advancing of the coal mining face. The scope of the abnormal zone would be increased with the coal mining face forward advanced. Thus the water f low cracks would be connected with the plastic failure and high resistance zone. When the plastic failure high resistance abnormal scope and range red uced,a water inrush from the roof could be predicted. Affected by the mining,the application of the overburden strata electric property variation law coul d be favorable to accurately detect the roof water deposition status in order to protect the safety mining of the coal mining face.