Application Of Multi-Electrode Resistivity Method And Ground Penetrating Radar In Karst Cave Exploration

Carbonate rocks are widely distributed in Anhui province.There are limestone distribution in Carboniferous,Permian and Triassic.Under the influence of tectonic fracture,groundwater is destroyed and karst is developed.Karst collapse is one of the common geological disaster,because of the karst cave has hidden strong,spatial distribution characteristics of karst collapse is poor,it i s difficult to predict,under external loads,karst cave roof collapse time and space it is difficult to predict,seriously threaten the safety of construction engineering.So in the karst area,how to adopt appropriate exploration methods and advanced,id entify the situation of karst,karst construction project scope,to speed up the construction progress,save project investment and has important significance to ensure the safety of the project.The theory combined with practice is based on the survey and evaluation project of karst collapse in Huainan area(Jiulonggang)in Anhui province(karst entrust2016-039),this paper summarizes the application of geophysical prospecting methods in karat cave exploration,combined with the geological conditions of the work area,geophysical characteristics and the limited conditions to exclude other geophysical methods,and chooses multi-electrode resistivity method,ground penetrating radar method to study and research.The main results and conclusions are as follows:(1)Using two geophysical methods,the cave 5 is found in the working area,and the scale and location of the cave are determined;(2)The geophysical parameters of the area are modified.The resistivity of the measured area is 8-30?·m,and the limestone resistivity is 200-5000?·m.The dielectric constant of the overburden is 10-15,and the dielectric constant of limestone is 7.5-8.5;(3)Through the two geophysical methods,three kinds of karst caves with different filling conditions were simulated,and the characteristics of karst cave with different filling conditions were obtained;(4)Other geological problems such as geological stratification,geological structure,karst fracture zone and so on are identified;(5)The suitability and effectiveness of two geophysical methods are reviewed.