January 7-11, 2018
Washington, D.C.
TRB 97th Annual Meeting

Static and Seismic Design of Piles for Downdrag

Sunday, January 07, 2018, 1:30 PM-4:30 PM, Convention Center
Sharid Amiri, California Department of Transportation (CALTRANS); Kenneth Fishman, McMahon and Mann Consulting Engineers, P.C., presiding
Sponsored by Standing Committee on Seismic Design and Performance of Bridges; and Standing Committee on Foundations of Bridges and Other Structures

The AASHTO Load and Resistance Factor Design Bridge Design Specifications acknowledge that piles in settling soil experience downdrag forces from negative skin friction. Many bridges are constructed in areas with compressible or liquefiable soils, necessitating the consideration of downdrag forces and associated settlement. Downdrag conditions place greater demands on foundations and may lead to higher construction costs. This workshop considers the fundamental behavior of piles subject to downdrag and reviews the neutral plane method.

Static and Seismic Design of Piles for Downdrag
Timothy Siegel, Dan Brown and Associates, PC

The AASHTO LRFD Bridge Design Specifications recognize that piles in settling soil experience downdrag forces from negative skin friction.  Many bridges are constructed in areas where there is compressible soil or liquefiable soil which necessitates the consideration of downdrag forces and associated settlement. Downdrag for static and seismic conditions places greater demands on foundations and may lead to higher construction costs. This workshop will consider the fundamental behavior of piles subject to downdrag and review the utilization of the neutral plane for the evaluation of downdrag and the static and seismic design of piles.