Tuhin Basu & Associates, Inc.

This prominent design-build bridge replacement project features the longest cable stay span in North America at 1546 feet and is the single largest infrastructure project in the State of South Carolina.  The replacement bridge is approximately 3 miles in length connecting the historic Charleston peninsula with the city of Mount Pleasant.  The structure includes major interchanges on the Charleston and Mount Pleasant sides of the channel.  

 

As part of the Palmetto Bridge Constructors team, Tuhin Basu & Associates, Inc. provided final design services and prepared final construction plans for ramps on Lines 11 & 16 in the Mount Pleasant Interchange section of the project.  Line 11 of this project is a 12 span, 1640-foot long, variable width, curved ramp structure with a 3,000-foot radius and connects to the high-level approach spans

of the mainline structure.  The Line 16 ramp structure is a two span curved structure on a 364-foot radius and connects to the Line 11 structure.  The superstructure of Lines 11 & 16 consists of prestressed concrete girders made continuous for live load and the substructure is comprised of single column hammerhead bents and two-column bents, several with post-tensioned bent caps.  All substructure units of Lines 11 and 16 are supported on drilled shaft foundations and the structure was designed for Seismic Performance Category D.  The span lengths are generally 140 feet in length.  This fast-track design-build project required extensive coordination with the contractor and other members of the design team.  TBA also provided construction support services for this project, such as shop drawing reviews and responding to contractor RFI's.