Inelastic behavior and ductility capacity of reinforced concrete bridge piers under earthquake. I: Theory and formulation

Analytical models for the inelastic behavior and ductility capacity of reinforced concrete bridge piers under earthquake are presented. The models for material nonlinearity include tensile, compressive, and shear models for cracked concrete and a model of reinforcing steel where the smeared crack approach is incorporated. An interface element is used to account for local discontinuous deformations at the boundary plane caused by abrupt changes in stiffness where members with different thicknesses are connected. An analytical model is developed to express the confining effects of lateral ties that depend on the amount of transverse reinforcement. Experimental verification and results from numerical simulations are presented in the companion paper.