Numerical Modeling of Soil-Shaft Interaction Validated Using the Instrumented Hayward Bridge in California-Video

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Video Summary

The study models soil–shaft interaction at California’s instrumented Harvard Bridge as part of a broader project to assess bridges rapidly after earthquakes. The University of Nevada, Reno team focused on geotechnical behavior, using OpenSees to model free-field ground response and a bridge shaft’s seismic response. Two recorded earthquakes were used to validate the free-field model against borehole measurements. Simulated surface displacements and spectral displacement responses generally matched observations, while some acceleration and spectral results differed, possibly because soil-property data were incomplete and damping values had to be estimated.<br /><br />The researchers then modeled a shaft using earthquake displacement histories and depth-dependent p–y springs representing stiff clay and weak rock. The model estimated shaft displacement and soil reaction under seismic loading. The presentation concludes that numerical modeling can help estimate ground and foundation responses where direct measurements are unavailable, while noting that some interface parameters were assumed rather than calibrated to observed behavior.

Keywords

soil-shaft interaction

earthquake modeling

OpenSees

free-field ground response

bridge seismic response

p-y springs