Arthur Ravenel Jr. Bridge

In 1987, S&ME completed a geotechnical exploration in support of the first study to replace the John P. Grace and Silas Pearman bridges across the Cooper River and conducted initial tests on the ground to understand its properties. In 1993, we performed additional tests to support another study for the same project. By 1999, S&ME joined a team chosen by the South Carolina Department of Transportation (SCDOT) to design the new bridge, which was planned to be over 15,000 feet long with a main span of more than 1,500 feet and a vertical clearance of about 190 feet.

During the first phase of this design contract, our S&ME team developed detailed plans and specifications for an extensive pile load test program worth over $6 million. This program aimed to test the strength and stability of large foundation shafts that would support the bridge. S&ME engineers supervised the tests, which were carried out at three different sites and tested the shafts, which were 100 to 150 feet long and 6 to 8 feet in diameter, using various methods to ensure they could handle both vertical and sideways forces. One site in Mt. Pleasant also included seismic tests to see how the soil would behave during a simulated earthquake.

Additionally, S&ME analyzed the shafts to provide design information for constructing forty-seven 7-foot diameter shafts in an early stage of the project and also examined the stability of the riverbed to determine the final length of the bridge’s main span. In the second phase of the project, S&ME conducted further explorations, drilling over 85 test holes and using other methods to study the ground along the planned bridge path, including deep borings for the main support piers.