COMPLEX GEOLOGICAL STRUCTURE INDENTIFICATION AND PARAMETER ESTIMATION METHOD BASED ON 3D RESISTIVITY MEASUREMENT

Geologic body usually presents complex three-dimensional spatial distribution in actual engineering. Traditional high-density resistivity method based on the assumption of two-dimensional medium may not be able to accurately reflect its spatial position and trend, while three-dimensional high-density resistivity method can handle such problems perfectly. But it is restricted in application due to the difficulty in data acquisition and processing. This paper attempts to study the effect of three dimensional high-density resistivity method in the exploration of unfavorable geologic bodies with complex spatial form and compare the difference from two-dimensional resistivity method. This paper firstly studies the principle and data processing method of three-dimensional high-density resistivity method, and then carries out the application research through the field test which is based on the goaf in Fujian Shouning. Both two-dimensional and three-dimensional high-density resistivity methods are used in the exploration. The results are verified by three-dimensional laser scanning. It successfully realizes the three-dimensional resistivity data acquisition of 240 electrodes in complex terrain, introduces the least square method based on the smooth constraint technique and finished the inversion of three-dimensional resistivity data. The research results show that three-dimensional laser scanning can accurately acquire goaf form and trend, which verifies the results of the resistivity method reliably. The three-dimensional high-density resistivity method can accurately reflect the location and trend of abnormal resistance. Compared with the two-dimensional high-density resistivity method, its inversion converges, which eliminates the deep interference information and reduces multiplicity of solution.