Techniques for detecting underground space in hidden karst region: Taking Wuhan as an example

The concealed and sudden karst collapse is the one of common geological environmental problems in the utilization of underground space in urban hidden karst areas. Research on the detection technology and methods of underground space structure in hidden karst areas may guide the utilization of underground space effectively. The degree of karst development, thickness and structure of the overburden, groundwater were proposed to be the primary geological conditions of karst collapse, which were characteristic factors of underground space exploration in hidden karst region, on the basis of analyzing the cause mechanism of karst collapse in Wuhan. The applicability of detecting underground space in hidden karst region was compared with ground penetrating radar, high density resistivity, shallow seismic, microtremor, multi-source surface wave, transient electromagnetic cross-hole computerized tomography and surface nuclear magnetic resonance. The results show that ground penetrating radar is suitable for detecting shallow soil disturbances. Both high density resistivity with small polar distance and multi-source surface wave are suitable for detecting the thickness and structure of the overburden. The shallow seismic, microtremor and cross-hole computerized tomography are suitable for detecting characteristics of karst development. Surface nuclear magnetic resonance can be used to evidence the degree of karst development through water abundance of karst groundwater.