Capacity Design of Bridge Piers and the Analysis of Overstrength

Keywords: Capacity design. Bridge columns. Overstrength. Plastic hinges. Reinforced concrete columns. Moment curvature analysis. Deterministic methods. Confinements. Stress block interaction. Simplified methods.

Abstract: The capacity design philosophy has now become the design norm for the seismic design of most structural systems. For bridge systems, this means it is necessary to assess the overstrength capacity of columns prior to proceeding with the design of the foundation and superstructure. This research is devoted to developing deterministic procedures to obtain overstrength factors for column elements. For this purpose, a moment-curvature approach is explored. A parametric study is then conducted to investigate the factors that affect overstrength. A simplified design methodology is proposed based on plastic analysis of overstrength moment capacity. A design example showing the step by step procedure is also presented.