瞬变电磁法在地下溶腔探测中的应用——以湖北应城盐矿为例

盐矿通常采用水溶法开采,经多年开采后,容易形成地下溶腔,造成地面沉降,所以需要采用有效的地球物理勘探方法查明采盐区地下溶腔的分布情况,为制定防治措施提供有价值的基础资料。利用瞬变电磁法具有对低阻异常反映灵敏的特点,采取加大发射电流、增加重复观测次数及避开地表电磁干扰等技术措施,确保了数据采集质量。通过先进的数据反演软件进行数据处理解释,基本查清了地下溶腔的分布情况。该探测成果取得了较好的实际效果,对以后解决类似地质问题具有一定的借鉴意义。

Application of transient electromagnetic method in underground dissolved cavity detection:case of salt mine in Yingcheng,Hubei Province

Salt mine is usually exploited by water-dissolving method that is prone to form dissolved cavity after years of exploitation, causing land subsidence.Therefore, it is needed to use effective geophysical prospecting methods to explore the distribution of underground dissolved cavity in salt mined area, which could provide valuable basic information to taking preventive measures for salt mines.By using transient electromagnetic method that is sensitive to the low resistance anomaly, and adopting several technical measures including increasing the emission current, multiplying observation times and avoiding the surface electromagnetic interference, the acquisition data quality is ensured.In addition, the underground cavity distribution is located through data processing and interpretation by advanced data inversion software.The results of this survey have good practical effects, which can provide reference to solving the similar geological problems in the future.