二维大地电磁反演及其在铁路长大隧道勘探中的应用研究  

2D Magnetotelluric Inversion and Its Application in the Exploration of the Large Railway Tunnel

作　　者：余年[1,2] 李坚[2] 王绪本[1] 

机构地区：[1]成都理工大学地球探测与信息技术教育部重点实验室,成都610059 [2]中铁二院工程集团有限责任公司,成都610031

出　　处：《工程地球物理学报》2009年第5期598-602,共5页Chinese Journal of Engineering Geophysics

基　　金：国家863高技术研究发展计划(编号:2006AA06Z110);铁道部长大隧道综合勘探及集成技术研究(编号:2006G008)资助

摘　　要：首先对多种反演方法的特点进行介绍，然后分析比较以Bostick变换为初始模型的OCCAM反演和非线性共轭梯度反演，指出Occam反演对初始模型依赖性小但反演速度慢，非线性共轭梯度反演对初始模型依赖性大但反演速度快的问题，进而提出以Occam反演作为初始模型的非线性共轭梯度改进方案。实践证明，改进的组合反演算法简便、快速，成像效果好。最后，用改进方法对南涪线梓里隧道（DK92＋406-DK97＋023）的大地电磁资料进行了处理，其结果对褶皱、断层、岩溶等地质构造进行了较好的反应。In this paper, several common magnetotelluric inversion methods are introduced firstly. Analyzing and comparing the inversion results of the Occam and nonlinear conjugate gradient （NLCG） method by the initial model of Bostick transformation, points out that the dependence is small for Occam method to initial model but the inversion speed is slow relatively. And the NLCG method is opposite. So, we propose the improved multi--inversion methods by the initial model of Occam inversion result. The practical inversion result proves that the inversion speed of improved method is fast, simple and the result is perfect. In the last place, the magnetotelluric observation data obtained from ZhiLi tunnel （DK92＋ 406-DK97q-023） in Nan--Fu Line, and the result has good responses of the geological structure such as the fold, the fault and the karst.

关 键 词：大地电磁 反演 OCCAM 非线性共轭梯度 铁路长大隧道 

分 类 号：P631.3[天文地球—地质矿产勘探]