Study On The Failure Law Of Floor From A Set Coal Mining In Paner Coalmine By Parallel Electrical Method

The goaf,formed after the coal mining,would cause coal seam and surrounding rock lose stress balance, thus the floor is deformated and damaged under the mining influence. Once it breakover the aquifer, the inrush would happen,which would cause the serious casualties and economic losses. With the increase of the mining depth and intensity, hdrogeological conditions of working face become more complex, and because of the increase of the in-situ stress,the threat of water disasters becomes more prominent. So increasing the investigation of the rule of the deformation and damage of the floor from coal steam mining would be an important task to prevent and control the coal mining water disaster.Under the analysis and investigation of the existing theory of inrush and the research of the floor damage detection, this paper puts forward the method of using the parallel electric testing system to detect the floor damage, based on the geophysical characteristics of the floor, which is the response characteristics of the floor deformation and destruction on the electrical parameters. By combining with the11223working face mining conditions of3coal seam from A set coal in Paner coal mine, and arranging the borehole observation system, the data is mom’ tored with the parallel electrical method. Then the data is processed from three aspects of a single hole electrode current relations, the electrode current inversion and double holes resistivity CT. The results show that by the position of the electrode current change, the damage depth of coal floor of the11223working face was19m. The current inversion profiles and resistivity CT profiles can intuitively reflect the deformation and destruction law of floor failure. The characteristics of rock which affected by mining was displayed typically when the current ratio of the coal floor strata is below0.5, and the resistivity value is3or4times to the background resistivity value. And there is a certain advanced stress influence in coal floor damage, the impact range is usually0-15m.Finally the roof and floor line monitoring results support the accuracy of the monitoring results of the drilling system. So the practical application results show that the technology can realize the effective detection of the damage rule of the floor in workface. And its adaptability is so strong that it has high application promotion value.At the same time this paper points out the problems existing in the floor damage parallel electrical testing technology, and the development direction in the future.