屏蔽电极法数值模拟

提出了屏蔽电极法——一种通过电流补偿来改变地下电流密度分布,从而突出深部目标体的异常,达到提高电法勘探深度目的的方法.先从理论上作了分析,然后利用ANSYS软件进行了直流电阻率剖面和电阻率测深法的模拟计算.结果表明,当屏蔽电极的位置和补偿电流的大小选择合理时,屏蔽电极法较之一般直流电阻率法的探测深度有明显提高,提高程度与地质体本身的形态、产状有内在的联系.理论分析和数值模拟都说明了该方法能够有效地提高直流电阻率法的勘探深度.

THE NUMERICAL SIMULATION OF THE SCREEN ELECTRODE METHOD

The Screen Electrode Method(SEM) is an electro-exploring method which can emphasize anomaly of the deep object and increase the detecting depth of the electro-exploring method through changing the distribution of the underground current density by the current compensate electrode.First of all,the distribution of the current density in the uniform half space is theoretically analyzed in this paper when the screen electrodes are arranged at the earth's surface.Then simulating calculation of profiles and soundings of the DC electro-exploring method are numerically carried out,supported by ANSYS that is a software based on the finite element analysis method.The calculation results show that the detecting depth of SEM is deeper than that of the common DC electro-exploring method when the locations of the screen electrode and the intensity of the compensate current are rationally selected.The theoretical analysis and simulating calculation show that the SEM can efficiently increase the detecting depth of the DC electro-exploring method.