Using Electrical Resistivity Tomography and Surface Nuclear Magnetic Resonance to Investigate Ground collapse at the DongMafang Salt Mine in Yingcheng, Hubei Province, China

Abstract:

Rock salt, for it is water-soluble, can be harvested through solution mining. In solution mining, wells are erected over salt beds and water is injected to dissolve the salt, and then the salt solution is pumped out. However, it can lead to brine overflow at the same time, which will intrude into the surrounding sand layers and form soil caves, and thus lead to ground subsides. Based on the characteristics, this study has applied a comprehensive geophysical method combining Surface Nuclear Magnetic Resonance (SNMR) and Electrical Resistivity Tomography (ERT) method. Because SNMR is the only known approach to directly find water, and it helps to determine if the low resistivity anomalies are caused by water. SNMR can also quantify the performance of hydrological parameters such as the depth of the aquifer and water content. This paper uses SNMR combined with ERT to investigate the ground collapse in Dong Ma Fang Salt Mining Area and provides a strong geophysical basis for future treatment measures.