Seismic Design and Retrofit Best Practices Workshop
To kick off the Sixth National Seismic Conference on Bridges and Highways, held in Charleston, South Carolina, FHWA offered its Best Practices for Seismic Design and Retrofit of Bridges Workshop to more than 85 attendees. This “Pre-Conference Workshop,” opened by Workshop Facilitator Reggie Holt, Senior Structural Engineer, FHWA Resource Center, was held on Sunday, July 27. The workshop provided participants with information covering a host of vital seismic issues. Presentations are listed below:
- Best Practices for Seismic Design and Retrofit of Bridges (pdf), Reggie Holt (moderator), Senior Bridge Engineer, Federal Highway Administration
- Seismic Lessons Learned (pdf), Phil Yen, Research Structural Engineer with FHWA’s Turner-Fairbank Highway Research Center
- Seismic Hazards and
Fundamentals (pdf), Derrell Manceaux, Senior Structural Engineer with the FHWA Resource Center
The presentation touches on 1000 yr. Hazard Maps - Upper Level EQ; 100 yr. Hazard Maps - Lower Level EQ; Response Spectra Definition (Amplification and Damping Effects & Effects of Site Soil Conditions); Three Point Design Spectra.
- Seismic Analysis and
Response Fundamentals (pdf), Lee Marsh, Structural Engineer, and Berger Abam
Topics include: Earthquake Loading (Inertial Forces); Modeling Guidelines (Types of Models); Choosing Analysis Techniques; Regular vs. Non-Regular Bridges; Elastic Force and Displacement Demand; Elastic Design vs. Actual Forces & Displacements; Ductility & Inelastic Behavior Fundamentals; Orthogonal Force Combination (Long. & Transv.); Multi-Modal Coupling (CQC, RMS).
- Force Based Design
Fundamentals (pdf), Ian G. Buckle, Director of Civil Engineering at the University of Nevada, Reno
Details are provided on: Elastic Forces vs. Modified Design Forces; Controlling Forces for Design; Strength Capacity of Bridge Members; Member Expected Strength; Member Over-strength (Manders); Plastic Hinging Forces; Phi factor change (P-Delta).
- Displacement Capacity Design Fundamentals (pdf), Roy Imbsen, Structural Engineer
The presentation centers on: Displacement Capacity Design Approach (background); Ductile Response (full & limited ductility); Implicit Deflection Capacity; Pushover Analysis Capacity; Moment Curvature; and Inelastic Deformations.
- Seismic Design and Retrofit Detailing Fundamentals (pdf), Reggie DesRoches, Professor of Engineering, Georgia Institute of Technology University
DesRoches provides essential information on Support Length Details & Requirements; Capacity Protection Philosophy and Details ; Detailing for Ductility (laps, confinement); Earthquake resisting Systems (ERS); and Typical Retrofit Details.
- Geotechnical Considerations (pdf), Anoosh Shamsabadi, Senior Bridge Engineer, California Department of Transportation
The presentation provides specifics on Liquefaction; Liquefaction Mitigation; Surface Fault Rupture; and Near Fault Effects.
- Workshop Summary Q & A (pdf), Reggie Holt (moderator), Senior Bridge Engineer, Federal Highway Administration
The workshop was well-received by participants; Evaluation results received an aggregate score of 4.03 out of 5.0.