1st Edition

Seismic Design Aids for Nonlinear Pushover Analysis of Reinforced Concrete and Steel Bridges

By Jeffrey Ger, Franklin Y. Cheng Copyright 2012
    400 Pages 177 B/W Illustrations
    by CRC Press

    400 Pages 177 B/W Illustrations
    by CRC Press

    Nonlinear static monotonic (pushover) analysis has become a common practice in performance-based bridge seismic design. The popularity of pushover analysis is due to its ability to identify the failure modes and the design limit states of bridge piers and to provide the progressive collapse sequence of damaged bridges when subjected to major earthquakes. Seismic Design Aids for Nonlinear Pushover Analysis of Reinforced Concrete and Steel Bridges fills the need for a complete reference on pushover analysis for practicing engineers.

    This technical reference covers the pushover analysis of reinforced concrete and steel bridges with confined and unconfined concrete column members of either circular or rectangular cross sections as well as steel members of standard shapes. It provides step-by-step procedures for pushover analysis with various nonlinear member stiffness formulations, including:

    • Finite segment–finite string (FSFS)
    • Finite segment–moment curvature (FSMC)
    • Axial load–moment interaction (PM)
    • Constant moment ratio (CMR)
    • Plastic hinge length (PHL)

    Ranging from the simplest to the most sophisticated, the methods are suitable for engineers with varying levels of experience in nonlinear structural analysis.

    The authors also provide a downloadable computer program, INSTRUCT (INelastic STRUCTural Analysis of Reinforced-Concrete and Steel Structures), that allows readers to perform their own pushover analyses. Numerous real-world examples demonstrate the accuracy of analytical prediction by comparing numerical results with full- or large-scale test results. A useful reference for researchers and engineers working in structural engineering, this book also offers an organized collection of nonlinear pushover analysis applications for students.

    Overview of Seismic Design of Highway Bridges in the United States
    Introduction
    AASHTO Bridge Seismic Design Philosophy
    Direct Displacement-Based Design Procedures

    Pushover Analysis Applications
    Displacement Capacity Evaluation for the Seismic Design of New Bridges
    Performance Level Verification for New Bridges Designed by DDBD
    Capacity/Demand Ratios for the Seismic Evaluation of Existing Bridges
    Quantitative Bridge System Redundancy Evaluation
    Moment–Curvature Curves and Axial Load–Moment Interaction Curves
    Other Applications

    Nonlinear Pushover Analysis Procedure
    Introduction
    SOL01—Elastic Static Analysis
    SOL04—Nonlinear Static Pushover (Cyclic or Monotonic) Analysis
    Material Library
    Element Library
    Material-Element Cross Reference

    Nonlinear Bending Stiffness Matrix Formulations
    Bilinear Interaction Axial Load–Moment Method
    Plastic Hinge Length Method
    Constant Moment Ratio Method
    Finite Segment–Finite String Method
    Finite Segment–Moment Curvature Method
    Concrete Column Failure Modes
    Bilinear Moment–Curvature Curves
    Column Axial Load–Moment Interaction
    Column Axial Load–Plastic Curvature Capacity Curve

    Analytical Formulation for Structures
    Joint Definition and Degrees of Freedom
    Inelastic IE3DBEAM Element
    Finite-Segment Element
    Brace Element
    Plate Element
    Unbalanced Forces

    Input Data for INSTRUCT Program
    Notes on Input
    STRUCTURE—Define the Structural Model
    SOL01—Elastic Static Solution
    SOL04—Incremental Static (Pushover) Solution
    BUG—Set Bug Options
    READ—Read Plot Files
    NOECHO—Inhibit Input Echo
    DUMP—Print Memory
    RELEASE—Release Memory
    STOP—Terminate Execution

    Numerical Examples
    Structural Limit State Indicators
    Member Yield Indicators
    Numerical Examples

    Appendix A: Stiffness Matrix Formulation for Bilinear PM Method
    Appendix B: Stiffness Matrix Formulation for Finite Segment
    Appendix C: Unbalanced Forces of a Finite Segment
    Appendix D: Nonlinear Incremental Solution Algorithms
    Appendix E: Plastic Curvature Capacities and Neutral Axis Depth in Columns
    Appendix F: Elastic and Inelastic Time History Analysis
    Appendix G: Elastic and Inelastic Response Spectra
    Appendix H: Response Spectrum Analysis of Multiple-dof System
    Appendix I: Polynomial Curve Fitting
    Appendix J: Plate Element Stiffness Matrix

    References
    Index

    Biography

    Jeffrey Ger, PhD, PE, is the Federal Highway Administration (FHWA) Division Bridge Engineer in Florida, Puerto Rico, and U.S. Virgin Islands. His research experience has been in the field of earthquake engineering, nonlinear structural response, and building and highway bridge design. He has published more than 40 technical papers in structural engineering. Dr. Ger received the U.S. Secretary of Transportation’s Team Award in 2004 "for providing extraordinary transportation services to move food, water and shelter materials to relieve the pain and suffering by millions of victims of the 2004 Hurricanes." He provided critical support in the wake of Florida’s 2004 hurricanes, completing an emergency interstate bridge repair project 26 days ahead of schedule. In 2006, he received the FHWA Bridge Leadership Council’s Excellent Award, recognizing his outstanding customer service in carrying out the bridge program in Florida. He received the FHWA Engineer of the Year Award and an award from the National Society of Professional Engineers in 2007, and in 2008 received the Civil Engineering Academy Award from the Department of Civil Engineering at the University of Missouri-Rolla. Dr. Ger was appointed as one of the seven members of the U.S. Transportation Infrastructure Reconnaissance Team that traveled to Chile in April 2010 to assess the bridge damage condition due to the February 27, 2010, Chile earthquake.

    Franklin Y. Cheng, PhD, PE, is a distinguished member (formerly honorary) of ASCE; a member of the Academy of Civil Engineers, Missouri University of Science and Technology (MST); and Curators’ Professor Emeritus of Civil Engineering at MST. He is one of the pioneers in allying computing expertise to large, complex, seismic-resistant structures. Dr. Cheng has received four honorary professorships abroad and chaired seven of his 24 National Science Foundation (NSF) delegations to various countries for research and development cooperation. He has served as either chairman or member of 37 professional societies and committees. Dr. Cheng has served as a consultant for Martin Marietta Energy Systems Inc., Los Alamos National Laboratory, and Martin & Huang International, among others. The author, coauthor, or editor of 26 books and over 250 publications, Dr. Cheng is the recipient of numerous honors, including the MSM-UMR Alumni Merit, ASCE State-of-the-Art (twice), the Faculty Excellence, and the Halliburton Excellence awards. In 2007, he was elected as the 565th honorary member of ASCE since 1852. Dr. Cheng has numerous publications to his credit, the most recent being Structural Optimization: Dynamic and Seismic Applications, Smart Structures: Innovative Systems for Seismic Response Control, and Matrix Analysis of Structural Dynamic: Applications and Earthquake Engineering.