Event

AEG Oregon Chapter - January 2024 Meeting (joint w/ ASCE)

Abstract:

The Oregon Department of Transportation is performing seismic retrofit and widening of the existing I-205 Abernethy Bridge over the Willamette River. The Abernethy Bridge is approximately 1/2-mile-long and supported on 14 piers bearing on a combination of spread footings and driven pile foundations due to the varying depth of basalt bedrock. Highly variable and challenging geologic conditions along the bridge alignment included deep liquefiable soil deposits along the east bank of the river, highly variable basalt bedrock elevation on the west bank of the river, and artesian groundwater conditions within the basalt. Seismic analyses for the retrofit and widening included 2D non-linear site response analysis of the bridge alignment to evaluate liquefaction, pore pressure development, and the deformation response of the bridge profile. The analyses indicated deep seismically induced lateral deformations at some pier locations resulting in significant foundation demands. A combination of large diameter drilled shafts and ground improvement was selected to support the structure and provide resistance to seismic-induced lateral deformations. The design included 6- to 12-foot-diameter drilled shafts extending to over 240 feet in depth as well as jet grout and deep soil mixing ground improvement up to 150 feet below the ground surface. This case history presents an overview of the geologic conditions, seismic design challenges and foundation solutions, highlighting unique aspects of the project
design.

Speaker Bios:

James Walters, PE, Shannon & Wilson, Inc.

James Walters joined Shannon & Wilson in 2013 after completing his BS and MS degrees in Civil Engineering at Oregon State University. James is a project manager and design lead for major infrastructure projects throughout the Pacific Northwest and is currently the project manager and Engineer of Record for the Abernethy Bridge and Van Buren Bridge Projects. His expertise includes subsurface characterization, deep foundation design and construction, and ground improvement.

Eric Paslack, PE, Shannon & Wilson, Inc.

Eric Paslack is a project manager with 15 years of experience in geotechnical engineering for landslides, earthquake engineering, bridge foundations, retaining walls, and pavement design. He joined Shannon & Wilson in 2009 after completing his BS and MEng degrees in Civil Engineering at Oregon State University. As project manager for ODOT and local agency transportation projects, Eric has experience on more than 40 ODOT projects with Shannon & Wilson including the OR38: Scottsburg Bridge Replacement project, OR217 Auxiliary Lanes project, and the I-205 Abernethy Bridge project.

Tom Braibish, PE, Oregon Department of Transportation

Tom has 25 years of geotechnical engineering experience working on projects throughout the Pacific Northwest. He received a BS in Geology and MS in Civil Engineering from Portland State University and worked as a consulting geotechnical engineer in the late 1990s to early 2000s prior to joining ODOT in 2003. While at ODOT Tom has taken on roles as a geotechnical design engineer, consultant project manager, manager of the Geo/Hydro/HazMat section, and is currently the Region 1 Senior Geotechnical Engineer. He has taught several geotechnical engineering courses as an adjunct instructor at Portland State University. Tom served as a subject matter expert on the I-205 Abernethy Bridge project and coordinated reviews of the analysis and design of drilled shafts and ground improvements.

Location

Old Market Pub (View)
6959 SW Multnomah Blvd.
Portland, OR 97223
United States

Timezone: America/Los_Angeles

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Owner: Oregon AEG

On BPT Since: Nov 06, 2016

AEG Oregon

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