Interstate 880 – San Francisco , Oakland Bay
During the deadly “Loma Prieta” or the “World Series” earthquake on October 17, 1989, the third game of the World Series was about to begin. At 5:04 P.M., a powerful earthquake measuring between 6.9 and 7.1 on the Richter Scale began shaking the entire San Francisco Bay area for approximately 15 seconds.
In that short time, numerous sections of I880 and numerous sections of bridges collapsed. Many Bay Area bridge stuctures, overpass structures, and numerous support columns in and around the Bay Area were entirely devastated or structuraly compromised. Numerous off-ramps, expressway approaches, and bridge sections would have to be rebuilt. Because of the muddy unstable foundation areas underneath the highway structures, and the considerable siesmic activity in the area, a new solution to the problem had to be worked out. If traditional methods were used, about fifteen meters of mud would have to be removed before rebuilding could begin. Since geofoam EPS has had been installed and tested in damp soil conditions similar to this on numerous projects around the world, geofoam was decided to be the best option. Using geofoam EPS , less than one meter of the soft muddy soil had to be removed speeding up reconstruction considerably, while increasing stability of the area.
By the time the construction on that portion of I-880 was completed, 50,000 cubic yards of geofoamEPS was installed. To date, no problems have arisen regarding the application of geofoam EPS in the I-880 project.