Electric-field response based experimental investigation of unsaturated soil slope seepage

Rainfall is one of the important factors causing the failure of slope, such as the occurrence of transverse cracks and localized slumps. The process of rainfall seepage was studied with an indoor soil slope model based on the Network Parallel Electrical Method. The responses of geoelectric-field parameters were analyzed to infer the evolution process of rainfall seepage path. The variations of geoelectric-field parameters also contribute to our understanding of the behavior of groundwater seepage. The results show that the seepage velocity and seepage position of groundwater can be obtained according to the exciting current and primary field potential response characteristics of seepage field. The primary field potential, exciting current, spontaneous potential and apparent resistivity are sensitive to the water flow. When the position of the seepage surface reaches a certain electrode, the spontaneous potential, primary field potential and exciting current rapidly increase, while the apparent resistivity decreases gradually. The result of apparent resistivity can reflect the variation of the water content in the 3D structural soil slope and the position of infiltration surface. The results of study can provide the theoretical basis for studying the behavior of moisture flow in soil slope under rainfall condition.