Study On The Overburden Destruction From11-2Coal Seam Mining In Gubei Cocal Mine By Parallel Electrical Method

The range and depth value of deformation failure to roof caused by coal mining affect the safe production of the mine, so we need to obtain the failure condition and related parameter of the roof. Presently, the geophysics technology is a research hotspot concerning about detecting the range of overburden failure, and its detection accuracy and resolution are always attracting attentions. By means of laying electrical sensor in roof boreholes of the appropriate location in order to form effective detection space, the paper analyzes deformation and failure characteristics of roof rock by using parallel electrical method dynamic acquisition data testing to supply effective basic information for field application.Firstly,This paper introduces the formation mechanism and the develop process of the overlying strata, and separately analyzes empirical formula and the main influence factors of the height of caving zone, such as the overburden mechanical properties, soil structure characteristics,the deposit state of coal seam, and so on. Secondly, the paper has made a further explain on the acquisition and the imager processing of parallel electrical data, mainly including acquisition method, conventional processing method and high resolution. And the resistivity tomography has been also described in details at last. Thirdly, considering the relation between rock resistivity properties and geological structure, the author of this thesis bring the overburden failure into relation with parallel electrical method; Based on the theory of full-space high-accurate3D electrical resistivity method, the principles and building requirements for designing the dynamic monitoring system of water conducting fractures are put forward, which have been successfully reserve observation system used in electric method fort detection technology.By the application of parallel electrical technique in observation borehole from coal seam11-2of Gubei coal mine, field detection results show that leading infection, caving zone and fractured zone had been developed significantly in the current ratio section of several time and background detection and the resistivity inversion section about cross-hole, apparent resistivity values of elevated goaf area which had even reached5times more than that of the background locally increased continuously.The result shows that the application of parallel electrical method in detecting the evolution of water conducting fractures in coal seam floor is effective, and it can present the failure mode of coal seam floor in mining process, the height of caving zone and fractured zone used with the technology is identical with the consequence of neural network and regulation. This paper indicates the lack of the method and study direction in the days to come.