California Department of Transportation


Built in stages between the 1950s and the 1980s, I-5 is one of the main highways on the West Coast of the United States, paralleling the Pacific Ocean and serving some of the largest cities of the western part of the country. The structure where the incident occurred features a reinforced concrete substructure and embedded reinforced steel elements.


WJE engineers performed a variety of physical and nondestructive tests on the overpass concrete, including visual observation, acoustic impact testing, petrographic studies, compressive strength testing of concrete cores, and tensile strength testing of reinforcing steel. After testing and analyzing the samples, the team provided Caltrans conclusions regarding the condition of the concrete and recommendations for the repair or replacement of the concrete where necessary.