The Numerical Simulation Research Of High-Density Electrical Method In Karst Cave Exploration

In the karst development area there are a large amount of karst cave,bath,eth, To fing out the position of the karst is of great significance to ensure the safety of engineering construction. High density resistivity method, as a new method of resistivity exploration, is widely used in karst area of exploration, because it has the automatic data collection and measurement mode diversification, inversion process digital etc. However, there are many problems which have not been confirmed and explained in the field exploration. This paper research and explain those problems in the theory by using the finite element numerical simulation technology.The first chapter introduces the development of the high density resistivity method structure,system characteristics, and make a detailed explanation on all kinds of electrode arrary, the principle of the inversion software. The principle of the numerical simulation and the problem of grid division,error,boundary are intoeduced in the second chapter.The third chapter make a comparison between the numerical simulation results and the indoor model test results, by this way the numerical simulation is proved to be feasibility. The fourth chapter mainly discuss the exploration effect of the laying way of the pole. The pole array type, the selection of the largest pole pitch,the selection of the adjacent pole spacing,etc are dicussed from the view of the the apparent resistivity abnormal value and inversion effect. By constructing a three dimensional model in the ANSYS software the data changing which is brought by the line migration is analysed. Those research can provide some guidance on the pole laying in theory. All kinds of geological model are established in the ANSYS in the fifth chapter. By doing this the effect of the covering layer resisitivity, the basement rock resisivity,the covering layer thickness, the diameter and depth of the karst cave hole in the exploration are studied. It puts forward the effctt exploration’s biggest cover thickness and the minmum hole diameter under the depth of30m by combining with the field real statistical data.