Hydrogeologic Modeling for Interstate I-70 Depressed Section Underdrainage

The project is associated with expansion of the Indianapolis International Airport, which will require realignment and depression of a section of interstate I-70 for construction of an airplane taxiway over the road. The geotechnical investigation encountered three distinct water-bearing units, including a confined sand and gravel aquifer which was expected to be a significant source of discharge. Design of an appropriate underdrainage system to maintain pavement integrity was supported by a hydrogeologic investigation. Data from the hydrogeologic investigation, geotechnical investigation, and underdrainage design specifications were then modeled to predict groundwater inflows to the drainage system. Subsequently, collection of dewatering discharge volume information during roadcut excavation provided an opportunity for a critical evaluation of the model results.