Lateral Load Testing Program for the Cooper River Bridge, Charleston, SC

A design phase load testing program has been recently completed for the planned Cooper River Bridge in Charleston, SC. This $500 million (+/–) bridge is subject to major lateral loadings from seismic, vessel impact, and wind forces and thus the load testing program includes lateral testing as a significant component. A total of 12 drilled shaft foundations were subject to lateral loading at the three field test locations. The 2.5 m (8.5 ft) and 2.0 m (6.5 ft) diameter test shafts provide a measure of soil response during lateral loading with the following variations: 1) shafts with and without permanent steel liners, 2) cyclic loading in both sands and soft clays, 3) lateral loading at a high rate of displacement, 4) lateral loading using the split cylinder technique with embedded O-cells, and 5) test shafts loaded in sands which are subject to blast-induced liquefaction during the test loading. The paper provides an outline of the overall testing program, comparisons of measurements of the test results with the variations cited above, and the interpretation and use of the test data to develop soil properties for design.