Characterizing Unknown Foundations to Improve Bridge Safety

completed

The unknown bridge foundations issue remains one of the most persistent problems facing the bridge engineering community. The National Cooperative Highway Research Program (NCHRP) Project 21-5 devoted considerable effort in developing new test methods to address this issue and some good progress was reported (Olson et al., 1996). However, there are still concerns on the reliability of the available technologies and associated costs, especially when they require the drilling of a borehole adjacent to the foundation. This activity would develop a multiyear research program to solve the Nation's unknown foundations problem and increase bridge safety. Innovations to be further pursued include identification that could lead to characterizing bridges with unknown foundations in terms of foundation type, material(s), depth, and integrity. One or more workshops will be conducted to identify approaches, reaching out to groups within and outside the normal bridge community. The product of these workshops will be a report detailing the best approaches to be taken and a plan of action to resolve this issue. The centerpiece of this program could be a full-scale outdoor laboratory to develop, test, and validate new and existing technologies for effective characterization of unknown foundations. Technologies to be developed, enhanced, and evaluated could include, but not be limited to, acoustic/seismic, electrical, magnetic, and radar. The exact nature of the program will be determined after receiving input from workshop participants.