MISSISSIPPI'S APPROACH TO UNKNOWN BRIDGE FOUNDATIONS

Unknown bridge foundations are experiencing higher priority by state departments of transportation. Within this scope lies perhaps thousands of piles for which no driving records exist. To help resolve this problem, a technology based upon the mechanics of dispersive stress wave propagation was developed by the principals of FDH, Inc., for finding unknown timber pile lengths. Since its original development, the technology has been expanded to address the problem of unknown pile lengths for other materials as well. Recognizing that unknown foundations are a problem, the Mississippi Department of Transportation (MDOT) recently implemented an aggressive program to evaluate bridges statewide. A multiyear, unknown foundation investigation program was initiated with Mobile, Alabama based FDH-North America, L.L.C., with the Department of Civil Engineering at Mississippi State University as project administrator. Presented are the results from two timber pile bridges that were tested using FDH methods and the piles subsequently extracted by MDOT to verify the technology.