NSR Over I-240 in Memphis, TN - A Case Study in CM/CG, Accelerated Bridge Construction and Seismic Design
(Room Ballroom A)
25 Sep 19
11:45 AM
-
12:15 PM
Tracks:
AREMA Technical Sessions By Date- Structures, AREMA Technical Sessions By Functional Group- Structures, Technical Sessions By Day- Wednesday
Benesch was the lead design firm for Tennessee Department of Transportation’s (TDOT’s) I-240 widening project in Memphis, TN. This project involved the replacement of the existing 316’-long, double track Norfolk Southern Railway (NSR) Bridge that carries 40.8 MGT over I-240. By teaming Benesch with Kiewit, TDOT employed the Construction Manager/General Contractor (CM/GC) alternative delivery method to replace the structures along the congested I-240 corridor. This collaborative process resulted in plans that met TDOT and NSR acceptance with constructability and cost input from Kiewit during the design process. In order to accommodate NSR operating requirements, the NSR replacement bridge was built using a temporary shoo-fly alignment supported on temporary substructure units. The shoo-fly alignment was highly constrained due to utility, ROW and track alignment requirements. Accelerated Bridge Construction (ABC) methods were employed to facilitate the use of the new 338’ long, 5-span, double track, ballasted deck superstructure in both the temporary and permanent alignment locations. The superstructure was designed and detailed as two separate single-track bridges and then slid into place atop new permanent substructures, one single-track “half” at a time during two multi-hour single track outages and full closures of I-240. When in their final location, the two superstructure “halves” were connected to have a fully-waterproofed, common ballast trough. A significant seismic design effort was required to develop final designs for the bridge sub- and superstructures due to the site’s proximity to the New Madrid Fault. *Missed this Session or want to view it again? Stop by the VirtualAREMA kiosk located in the Registration area to purchase this product today!