高密度电法与等值反磁通瞬变电磁法在法泗岩溶塌陷精细探测中的联合应用

Combined Application of High Density Electrical Method and Opposing Coils Transient Electromagnetic Method in Fine Detection of Karst Collapse in Fsai

岩溶地面塌陷是岩溶地区因岩溶作用而发生的一种引起地面变形、破坏的地质灾害,是目前国内较为常见的地质灾害之一,性质上多表现为突发性和爆发性。该类地质灾害发生后,往往需要在很短的时间做出全面、准确的灾害评定,这就对地质灾害的快速、精细化探测提出了非常高的要求。本文以武汉市法泗镇岩溶塌陷为例,采用高密度电法、等值反磁通瞬变电磁法两种物探方法进行探测。通过资料处理和解释分析,认为两种方法均取得了一定的探测效果,但单一方法未能达到岩溶塌陷精细化探测的要求。基于两种方法反演成果数据均为视电阻率值,且两种方法优点互补,本次研究将两种方法的反演数据按照其变化规律进行整合拼接,保留高密度电法的浅部数据及等值反磁通瞬变电磁法中深部数据,扬长避短,形成一张探测成果图,实现了对岩溶塌陷快速、精细化探测的目的,为该区岩溶塌陷成因机理分析提供了科学的依据。该应用方法对以后解决类似地质灾害问题具有一定的借鉴意义。

Karst ground subsidence is a geological disaster that causes ground deformation and destruction due to karsification in karst areas.After the occurrence of such geological disasters,it is often necessary to make a comprehensive and accurate disaster assessment in a very short period of time,which raises very high requirements for the rapid and refined detection of geological disasters.In this paper,the high-density electrical method and the equivalent inverse flux transient electromagnetic method are used as an example to detect the karst collapse in Fasi town,Wuhan city.Through data processing,interpretation and analysis,it is concluded that both methods have achieved a certain detection effect,but the single method fails to meet the requirements of refined detection of karst collapse.Based on the fact that the inversion results data of the two methods are apparent resistivity values and the advantages of the two methods complement each other,the author integrates and splices the inversion data of the two methods according to their changing patterns,and retains the shallow data of the high-density electrical method and other methods.Through inverse magnetic flux transient electromagnetic method for mid-deep data,fostering strengths and circumventing weaknesses,the author forms a map of the detection results to the effect of rapid and refined detection of karst collapse,and provides a scientific basis for the analysis of the genetic mechanism of karst collapse in this area.The method has certain reference significance for solving similar geological disasters in the future.