A group of Murraysmith + Quincy’s regional experts in bridge engineering will be attending the 2021 Virtual Western Bridge Engineers Seminar from September 13-16. With over 300 bridge projects under our belt, we’re eager to exchange lessons learned with our industry colleagues and clients, contributing to the advancement of this field.
Here’s a taste of what our engineers will be presenting on.
September 3, 2021
Showcasing Three Bridge Designs – 2021 Virtual Western Bridge Engineers Seminar
On September 15 at 10:15am, Jeff Olson will be presenting on our team’s work to widen and seismically retrofit the Abernethy Bridge on I-205 in Portland, Oregon. Deemed a lifeline route, this project is critical to keeping the community safe in the event of an earthquake—in this case, the project team is designing the bridge seismic retrofit to meet two-tiered performance criteria. At the lower level, retrofits must allow the bridge to perform elastically so that it is usable (with limited repairs) for emergency service and economic recovery efforts following the Cascadia Subduction Zone earthquake—the primary seismic threat in the Pacific Northwest. At the higher level, the bridge is also being designed for life safety (no collapse) for the 1,000-year event.
Link River Bridge Seismic Retrofit – Tailored Solutions to Two-Tiered Performance Criteria
On September 15 at 10:45am, Josh Goodall will be presenting on part of the US97 Seismic Retrofit project: the 17-span Link River Bridge in Klamath Falls. The focus of the presentation will be on the challenges associated with Oregon’s two-tiered performance criteria and the retrofit strategies necessary to address complex seismic behavior resulting from a single bridge with varying superstructure and substructure types. Combining these dual criteria into a single, comprehensive retrofit strategy presents unique challenges where the ductility of existing bridge elements is balanced against the need for adequate strength to remain serviceable after substantial shaking. Applying these competing goals to a bridge with such material and geometric variety results in a thorough and creative implementation of many tried and true retrofit measures.
Interested to learn more but can’t make the seminar? Reach out to Greg, Jeff, or Josh directly!
Mosquito Road at South Fork American River Bridge – Nonlinear Foundation Analysis for Pile Footings Excavated into Steep Slopes
On September 13 at 2pm, Greg Young will be presenting on the team’s performance of a static nonlinear analysis on the piles and footing foundation for the proposed American River Bridge at Mosquito Road. This analysis was necessary because the pile footings will be excavated into the side of a steep canyon slope (1.3:1). Key considerations include: 1) high moment and shear forces in conjunction with reduced soil capacity in the downslope direction, 2) lateral group effects on various pile configurations, and 3) steep slope effects on foundation stiffness. Gavin Keating, out of the Rancho Cordova office, was also heavily involved in the analysis. Gavin’s highly proficient Excel skills were essential in pre-processing and post-processing data in the SAP model, which required over 52 unique soil springs assigned to over 260 individual nodes.