CSVT Bridge: Design and Construction Challenges

The CSVT River Bridge is a key component to a new 13-mile stretch of highway near Selinsgrove and Northumberland, Pennsylvania. The bridge is a six-lane, 15-span, 7/8-mile-long multi-girder structure comprised of three independent 5-span steel superstructure units. The eight 9′-6″-deep steel plate girders are spaced at 12′-3″ and reach a maximum span length of 350′.
The bridge substructure consists of hammerhead piers on either spread footings or drilled caisson foundations. Ranging from 70′ to 180′ above the footings, the pier heights vary along the length of the bridge. The height of the piers and the proposed pier stem cross-section places the piers outside AASHTO slenderness limits, which required advanced analyses of second-order effects in lieu of the typical approximate method used for estimating second-order effects.

This presentation covers the challenges of designing and optimizing long span steel multi-girders, lateral bracing, diaphragms, and slender piers, as well as the consideration of substructure system interaction. Construction challenges and issues will be discussed as well.

Presenters are:

Jason DeFlitch, PE, SAI Consulting Engineers, Inc.
Matthew T. Stahl, PE, Trumbull Corporation
Ahmad K. Ahmadi, PhD, PE, SAI Consulting Engineers, Inc.