Geologic and hydrologic aspects of tunneling in the Twin Cities area, Minnesota

This report presents the results of a pilot study of geologic and hydrologic aspects of tunneling in part of the Minneapolis-St. Paul (Twin Cities) metropolitan area, Minnesota. The Minnesota Geological Survey collected, compiled and interpreted geologic and engineering-test data and the U.S. Geological Survey complies and interpreted hydrologic data. The report was prepared on behalf of the U.S. Department of Transportation and funding was provided by that agency. A similar pilot study was recently made in the Los Angeles area, California (Yerkes and others, 1977).