Integrating Multiple Subsurface Exploration Technologies in Slope Hydrogeologic Investigation: A Case Study in Taiwan

This study aims at presenting an integration of different downhole prospecting techniques for hydrogeologic investigation in an active landslide area. A series of subsurface exploration technologies were conducted, including borehole image scanning, electric logging, groundwater velocity measurements, and double packer testing. Both acoustic and optical borehole loggings as well as electric logging were applied to identify lithology, water bearing capacity and fracturing of the formation around the boring. Subsequently, borehole flow logs were used to indicate the distribution of permeability and hydraulic connectivity of fractures along the borehole. Based on the above prospecting results, test sections of hydraulic tests can be arranged. Finally, hydraulic packer tests were carried out to further characterize the hydrogeologic system of the site and quantitatively determine the hydraulic properties of major hydrogeologic units. Integrating multiple downhole prospecting techniques on slope hydrogeology investigation not only provides hydraulic properties for a study area, but also brings information to establish a hydrogeologic conceptual model and process the model simulation.