In effort to enlarge its medical research facilities, Vanderbilt University performed a vertical expansion of its existing laboratory building and construction of a new connected tower that was built over the existing Langford Auditorium. VSL was selected as the post-tensioning supplier because of its diverse range of products and support for this challenging project.

The first phase of the project added 124,000 square feet of space in four new levels to the existing Light Hall building. VSL’s VSLAB+ bonded slab system was used in the floors of this new structure.

Constructing the structure involved in the second phase of the project presented unique challenges. The goal was to build a new tower to span and encapsulate an existing 1,200-seat auditorium without closing it or adding any supports within it. The engineer devised a unique post-tensioned concrete truss design to span 132 feet over the auditorium and support nine floors above with minimal deflection. Trusses were reinforced using bonded multistrand, threaded bars and unbonded monostrand systems. As each floor was added, the trusses were stage stressed to control member stresses and to minimize camber effects on subsequent elevated concrete slabs.