摘要
采用易于模拟复杂地形起伏和倾斜界面的非结构三角单元剖分网格,并利用对偶加权后验误差估计指导网格自动细化过程,实现了2.5维直流电阻率法自适应有限元数值模拟。在实例模型分析中,分别计算了层状模型和垂直岩脉模型的直流电阻率响应,并与其解析解进行了比较。对比结果表明,该算法所得数值解精度很高,解的相对误差小于0.5%。最后,计算了起伏地形2.5维地电模型视电阻率异常,并利用比较法进行了地形改正。地形改正结果与水平地形时的结果对比表明,比较法可以较好地消除地形影响,突出局部地质体异常。
2.5D DC resistivity modeling was realized by adaptive finite-element numerical simulation algorithm. This algorithm uses un-structured triangular element that is easy to simulate complex topography and inclined interface to subdivide mesh, and utilizes dual weighted posteriori error estimation guide mesh refining process. In the instance model analysis, the authors calculated the DC resistivity response of the layered model and the vertical dike model, which were compared with their analytical solutions respectively. The results show that the numerical solution for this algorithm has high accuracy,and the relative error of the numerical solution is less than 5 percent. Finally, the authors calculated 2.5D geoelectric model apparent resistivity anomaly of undulate topography and corrected the undulate to-pography by using the comparative method. The contrast between topographic correction results and level terrain results show that the com-parative method is effective in eliminating the terrain effect and giving prominence to local geological anomalies.
出处
《物探与化探》
CAS
CSCD
2014年第1期145-150,共6页
Geophysical and Geochemical Exploration
基金
国家自然科学基金(41204055
41130420)
关键词
直流电阻率
自适应有限元法
地形改正
2
5维
后验误差估计
DC resistivity
adaptive finite-element
topographic correction
2.5D
posteriori error estimation
