FHWA UNKNOWN FOUNDATIONS RESEARCH PROGRAM

Abstract

Following the catastrophic collapse of the Schoharie Creek Bridge on the New York State Throughway in April 1987, national attention has been focused on the bridge scour problem. Foundation characteristics are needed for accurate scour analysis—which was nonexistent for the Schoharie Creek Bridge. Therefore, as a consequence of addressing scour vulnerability of bridges, the unknown foundation became a national priority. Over the years, it is well recognized that the unknown foundations is not just important for scour studies but for other important structural and geotechnical evaluations such as foundation condition assessment and changes in service loads. Considerable effort has been devoted in developing new test methods with some good progress; however, there are still concerns on the reliability of the available technologies and associated costs. The Federal Highway Administration (FHWA) intends to initiate a multi-year research program to solve the Nation's unknown foundations problem. The purpose of this program is to develop and/or evaluate new and existing technologies for characterizing bridges with unknown foundations. To initiate the program, FHWA is planning an outreach program to define research gaps and needs through a workshop. The development of the research roadmap and the multi-year program will be completed after input from the planned workshop. In this paper, a summary of the nondestructive testing (NDT)/geophysical methods used to date and recent FHWA guidance is presented.