Numerical simulation for the influence of two-end grounded cables on georesistivity observation
Shi Fuqiang
Shao Huicheng
Zhang Guoqiang
Fang Wei
Abstract：Two-end grounded cables often generate interference to continuous georesistivity observation at fixed sites for earthquake monitoring and prediction in China.By taking the grounded cables as two-end grounded resistors and sim-plifying the medium of geoelectric observation sites into horizontally inhomoge-neous three-layered medium,a coupled physical model is built up in this paper. Based on this model,influences of two-end grounded cables on georesistivity observation are simulated under different electric structures by using the finite element analysis software ANSYS.Furthermore,the effects of interference fac-tors,such as position,azimuth and buried depth of electrodes,on georesistivity observation are analyzed.And the interference mechanisms are also discussed. Besides,some existing interferences are also presented to give out a comparative study.The results showed that the first,the grounded cables can cause local adjustment of the symmetric underground electric field distribution generated by the current electrode,affecting normal georesistivity observation;the second, the effects of grounded cables on georesistivity observation,mainly depend on position of cables and their azimuth;the third,the effects tend to be reduced obviously with buried depth of electrodes increasing;and the forth,the differ-ence of the electric structures determine the magnitude of interference.The sim-ulation results are of significance as a reference to analyzing the similar resistivi-ty anomalies,choosing the evaded distance of the interference source and the re-form of the observing system.
Keywords：georesistivitytwo-end grounded cablehorizontally inhomogeneous three-layered mediuminterferencenumerical simulation
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 1101-1112 )