Design Challenges and Solutions for the I-205 Abernethy Bridge Retrofit and Widening Project-PPT Presentation

PPT Presentation

Pdf Summary

The I-205 Abernethy Bridge project combines bridge widening to add travel lanes with a seismic retrofit. Design relied on nonlinear structural time-history analysis and geotechnical site-response evaluations.<br /><br />The bridge crosses varied subsurface materials, including fill, gravel and sand alluvium, fine-grained alluvium, decomposed basalt, and basalt. These conditions informed assessments of earthquake-related ground and structural response, including potential failure surfaces near dense or hard soils.<br /><br />The design team considered several mitigation strategies: ground improvement, increasing foundation or structural section sizes, and seismic isolation. Geotechnical and structural models were used to compare options, with cost evaluations included in the design process. Solutions were developed for specific bridge piers, reflecting the project’s differing site and structural demands.<br /><br />Overall, the project’s approach integrated geotechnical, structural, and economic considerations to address seismic risks while accommodating the planned widening.

Keywords

I-205 Abernethy Bridge

bridge widening

seismic retrofit

nonlinear structural analysis

time-history analysis

geotechnical site response

ground improvement

seismic isolation

foundation design

earthquake risk