2D Modeling And Inversion Of Cross-hole Resistivity Imaging Research And Application

Electrical prospecting is one of traditional geophysical exploration methods. It hasbeen widely applied in fields of geological examination, water controlling, and miningexploration, et al. resistivity tomography has the same as higher horizontal resolution ofelectrical profiling and higher vertical resolution of electrical sounding. It has been carriedout in2-D and2.5-D numerical calculation and practical materials, and applied in thehydrology, engineering, environment, archeology, mineral resource survey, oil-gasexploration. In this paper, through combining numerical simulation and physicalsimulation，and several typical geologic models were simulated by two-dimensional FiniteElement Method. At last drew some significant conclusions.In this paper, it analyzed and discussed the basic principles and, characteristics ofresistivity imaging techniques. Then through finite element numerical simulation andselect advanced Zohdy inversion do some jobs. It established a variety of numericalsimulation of theoretical models of2D modeling and inversion, and made someconclusions.Cross-hole RT technique research is leading content in the paper. Because ofcross-hole resistivity imaging technology (CRT) is putting the current electrode placedunderground, the measuring electrode also can be placed in the wells, and its ability todistinguish significantly higher than the ground form, but the nature of the borehole fluid,electrode position, electrode spacing,selection and the measurement of abnormal relativelocation of drilling, and so on, which will affect the results.So, all this reason made it isdifficult to give geophysicists the actual data, the correct processing and interpretation ofthe unknown difficulties. It does some research in low-resistivity cylinder, high-resistivitycylinder physical modeling and inversion of the theoretical model. By analysis of theinversion results, obtain some rules, and has practical value after proper processing andinterpretation of the actual data has a large practical significance in practical engineeringapplications.In practical applications, CRT has its own characteristics and advantages than otherimaging techniques, embodied in the following aspects: the low cost of field work by the small impact of the construction site conditions; easy construction technology, and wouldnot impose drilling damage. According to the basic principles of the resistivity imagingtechnique we known Cross-hole resistivity imaging in solving engineering geology andhydrogeology, coal mine water hazard prevention and control of subsurface fluid saturationmonitoring has a large potential for development and application prospects. Finally, thispaper describe the application of resistivity imaging techniques in the urban rail transit, andAnalysis and processing the collected data, which acquired the distribution of the bedrocksurface in work area, at the same time, it provides the necessary technical support for thepost-shield construction.