大地电磁约束反演在隧道勘探中的研究

研究目的:首先在OCCAM反演方法基本原理研究基础上,对OCCAM的目标函数进行修改,加入约束反演项,提出电性参数约束反演的概念,并进行电性参数约束反演模块的开发,最终提高大地电磁方法在长大隧道勘探中的分辨能力。研究结论:对比模型的常规反演和电性参数约束结果发现,利用先验信息的约束反演成像效果明显优于常规反演方法;将此方法应用到实际资料处理中,对比渝利线方斗山隧道电性参数约束反演前后结果,约束反演结果对褶皱、断层、岩溶等地质构造的反映更符合实际。

Study on Application of Magnetotelluric Constrained Inversion in Tunnel Exploration

Research purposes: Base on the study on the principle of OCCAM inversion method,the objective function of the OCCAM was modified,the constrained inversion item was added,the concept of constrained inversion of electrical parameter was proposed and the inversion of electrical parameter module was developed to improve the resolving ability of the magnetotelluric method for the exploration of large railway tunnel. Research conclusions:From the comparison of the model’s conventional onstrained inversion result with the electrical parameter result,it could be seen that the imaging effect of the constrained inversion with prior information was better than the conventional inversion.The method was used for the data processing,and the comparison of the results before and after constrained inversion for the Fangdoushan Tunnel showed that the constrained inversion results of the geological structure such as the fold,fault and karst more tallied with the real situation.