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Pier Pre-Construction Survey

San Rafael Bridge - Richmond, CA


Richmond-San Rafael Bridge Retrofit Project

CLE Engineering performed hydrographic surveys along 51 sets of piers along the San Rafael Bridge. There were six additional pier sets to be surveyed after marine life (sea lions and seals) vacated the pier areas. The bridge spans 4 miles and the surveys were all performed at 15’ and 20’ spacing around each set of piers. After all these surveys were completed, CLE created excavation models around each Pier and calculated total material amounts available to be dredged out to provide access for a seismic retrofit construction project around the pier bells. CLE encountered numerous challenges as survey lines had to be with an oblique current that often ran as fast as 7 or 8 knots. Additional challenges were setting up the excavation models in 3D for quantity calculations there are 4 different Pier configurations with six different bell sizes. Surveying around bridges also present unique challenges with positioning controls. Follow up phases for CLE included condition surveys and final surveys along with project quantity tracking.