垂直线源井-地电位探测地下动态导体的三维有限元数值模拟

The 3-D Finite Element Number Modeling of Vertical Line Source Borehole Ground DC Method Detecting Underground Dynamic Conductor

利用钻孔金属套管作为线源供电,在地表观察电位探测地下动态导体是一种实用的方法。在本文中,以垂直钻孔套管为垂直线源,介绍了垂直线源的地电场电位公式,给出了异常电位的变分问题。针对有限元方程求解时计算速度慢和对内存要求高的问题,利用对称超松弛预条件共轭梯度算法结合按行压缩存储技术,提高了计算速度并且减少了对内存空间的要求。采用异常电位的有限元法实现了井-地电位探测地下动态导体的三维数值模拟。通过一个低阻动态导体在不同埋深处模拟超大型垃圾场区渗滤液的地下去向,算例结果表明利用垂直线源井地电位三维有限元研究探测地下动态导体是有效、可行的。

It is a simple arid practical method to detect the underground dynamic conductor by vertical line source borehole--ground DC method. We presented the problem of anomalous potential and the geoelectric field potential formula of vertical line source in this paper. Combination of the symmetric successive over relaxation preconditioned conjugated gradient method （SSORPCG） with the compressed sparse row （CSR） method accelerated solution of the finite element equations and reduced the demand of memory. The 3--D finite element number modeling of vertical line source borehole--ground DC method is realized by the finite element method of anomalous potential. The penetration direction of in the ing place is simulated by a dynamic low--resistant conductor at different depths. The results showed that the algorithm in this paper is feasible and effective to detect the underground dynamic conductor by vertical line source borehole--ground DC method.