Water-flowing fault exploration of huge thick bedrock landslide based on wide-field electromagnetic method

Aiming at the engineering geological characteristics of the huge thick bedrock landslide, wide-field electromagnetic method and flow field fitting method were used on exploring the underground water and fault structure at different depths, and the interpretation results were verified by drilling and excavation prospecting. The results show that three low-resistivity rich water areas in the shallow are identified by wide-field electromagnetic method, and their distribution range and depth are basically identical with the interpretation conclusions of flow field fitting method, in which the boreholes of BZ-7 and BZ-8 in Y-1 rich-water area reveal confined water; in addition, the strata of low-resistivity water-rich area in the deep are presumed to be mesoproterozoic metamorphic rocks. Two electrical mutation anomaly zones which spread along the northeast-southwest trend and across the landslide are identified in the Palaeogene Xining group, and their positions and occurrences are highly consistent with F-1 and F-2 south poured reverse fault in excavation prospecting cave. It is conjectured that the F-1 reverse fault blocks the migration of deep groundwater to the river side, and the interaction of F-1 and F-2 reverse fault provides the channel for the seeping of rainfall and deep groundwater to the multilayer sliding zone of main sliding section. © 2021, Central South University Press. All right reserved.