The impact of a PEER funded research project “Influence of Vertical Ground Shaking on Design of Bridges Isolated with Friction Pendulum Bearings” is highlighted below. The project Principal Investigator is Keri L. Ryan, Associate Professor of Civil Engineering, University of Nevada, Reno.
Download the Research Project Highlight which includes the abstract. (PDF)
Research Impact
Performance-based design techniques are used for critical infrastructure that have seismic performance
objectives beyond minimum code requirements. Highway bridges are a critical component of resilient
transportation systems that support post-earthquake response and recovery. Seismic isolation techniques
are recognized as an effective option to reliably achieve high post-earthquake performance objectives
such as continuous operation. The influence of vertical shaking on the lateral response of systems with
friction pendulum bearings has been identified as a potential shortcoming that may prevent achievement
of envisioned performance objectives targeted through PEER performance-based earthquake
engineering methodology. However, prior research has shown that the influence of vertical shaking can
be reliably predicted through properly constructed models and analysis techniques. In this project, a
thorough parameter study will lead to more complete understanding of the significance of vertical
shaking on isolated bridges with a variety of response characteristics, and may ultimately lead to
recommended changes in the design of bridges isolated with triple pendulum bearings. If it is concluded
that vertical shaking should be considered, then follow-up work is anticipated to determine the specifics
of design guidelines for seismically isolated bridges. Efforts to determine specifics should be driven by
interaction and feedback with code committees, such as AASHTO or Caltrans.
