Forward and inverse numerical simulation of high density electrical exploration of stratified geological bodies
In order to determine the electrical characteristics and distribution rules of layered geological bodies such as land-slides in sounding work,a high-density electrical Wenner device is used for numerical simulation.Numerical models of two kinds of layered geological bodies with high and low resistivity of 5 m thickness are established respectively under different burial depths of 10 m,15 m,20 m,25 m,30 m and 35 m.After forward and inverse calculation,the detection depth of the high resistance model is AB/7,and the detection depth of the low resistance model is AB/8.With the increasing of the buried depth of the abnormal geological body,the influence range of the anomaly will gradually widen.The maximum value of the inversion of the high resistivity stratum will gradually decrease compared with the model,and the minimum value of the inversion of the low resistivity stratum will gradually increase.Through the engineering example under the background of low resistance,the detection depth is determined to be AB/6,and the position of the slide surface is effectively determined.After drilling verification,the results are reliable,and the average thickness of the slide is about 7.4 m.The results show that the effective detection depth of Wenner device is about AB/8-AB/6,the electrode spacing should not be greater than the thickness of abnormal strata,and the section line length should be as long as possible to ensure sufficient detection depth,which will make the exploration results more meet the actual situation.
High density resistivity methodstratified geologic bodyforward and inversionnumerical simulationland-slide
NETL
NSTL
万方数据
