341.2R-97
Seismic Analysis and Design of Concrete Bridge Systems (Reapproved 2003)
1997, 25 pp.
$58.50

This document, intended for use by practicing engineers, provides a summary of the state-of-the-art analysis, modeling, and design of concrete bridges subjected to strong earthquakes. The material in this report is intended to complement existing documents form AASHTO, Caltrans, and UBC. Procedures and philosophies of current and emerging codes and guidelines are summarized. Linear and nonlinear seismic analysis methods are also discussed, and important modeling considerations for different bridge elements including curved girders and skewed abutments are highlighted. The report summarizes analysis and design considerations for concrete bridges with seismic isolation as well as general seismic design considerations.

Contents:
Chapter 1 - Introduction

Chapter 2 - Codes

2.1 Historical Perspective

2.2 Current codes and manuals

2.2.1 AASHTO

2.2.2 Caltrans

2.2.3 NCHRP 12-33/AASHTO LRFD

2.2.4 Seismic analysis and design manuals

2.2.5 ATC-32

Chapter 3 - Analysis

3.1 Seismic input

3.1.1 Response spectrum analysis

3.1.2 Time-step analysis

3.1.3 Vertical accelerations

3.2 Single-mode spectral methods

3.2.1 "Lollipop" method

3.2.2 Uniform load method

3.2.3 Generalized coordinate method

3.3 Multi-mode spectral methods

3.4 Time step analysis

3.5 Nonlinear analysis

3.5.1 Nonlinear material behavior

3.5.2 Geometric nonlinearity

3.5.3 Methods of nonlinear analysis

Chapter 4 - Modeling

4.1 General

4.1.1 Global modeling considerations

4.1.2 Stiffness modeling considerations

4.1.3 Mass distribution

4.1.4 Modeling of secondary effects

4.2 Superstructure modeling

4.2.1 Stiffness considerations

4.2.2 Mass distribution

4.2.3 Damping

4.3 Superstructure/Foundations

4.2.1 Stiffness considerations

4.2.2 Mass distribution

4.2.3 Damping

4.4 Bearings

Chapter 5 - Design

5.1 General

5.1.1 Single span bridges

5.1.2 Design method

5.2 Design forces

5.2.1 Combination of orthogonal forces

5.2.2 Load combinations

5.2.3 Response modification factors

5.2.4 Forces resulting from plastic hinging

5.3 Design considerations

5.3.1 Bearing seats

5.3.2 Expansion joints and restrainers

5.3.3 Abutments

5.3.4 Shear keys

5.3.5 Hold-down devices

5.4 Seismically isolated bridges

5.4.1 Design principals of seismic isolation

5.4.2 Objective of AASHTO seismic isolation guidelines

5.4.3 Philosophy of AASHTO seismic isolation guidelines

5.4.4 Methods of ananlysis for seismic isolation design

5.5 Construction

5.5.1 Constructability

5.5.2 Seismic events during construction

5.5.3 As-built analysis

Chapter 6 - References

6.1 Specified references

6.2 Cited references