US 378 Bridge Over Great Pee Dee River Foundation Testing
Florence & Marion Counties, SC
The 4,032‘ long bridge carrying US-378 over the Great Pee Dee River was in serious disrepair and in need of replacement. The bridge was ranked #9 on the SCDOT’s statewide priority list for bridge replacements. In late 2007 after the initial design was completed by F&H, it was decided to evaluate the use of prestressed concrete cylinder piles as an alternative foundation type for this bridge. To this end, F&H performed extensive alternative studies and determined that 54-inch prestressed cylinder piles were a viable option for this bridge project. Although this foundation type was viable from a design perspective, it was necessary to determine if the piles could be installed to the required capacity and depth without adversely affecting the adjacent existing bridge. In order to accomplish this, F&H in conjunction with S&ME devised a testing program to evaluate the installation and capacity of both 54-inch cylinder piles and drilled shafts. This program was unique since it was performed in advance of construction, allowing the findings to be incorporated into the construction plans, resulting in more cost-effective bids for the bridge replacement. F&H also assisted the SCDOT with construction services, providing construction management, inspection personnel, and testing services. F&H performed all of the work associated with this program on an accelerated schedule to allow for the replacement of this critical bridge structure to occur on schedule.