Analytical Modeling and Design Validation of Posttensioned Precast Concrete Coupling Beams for Seismic Regions

Abstract

This paper provides an experimental validation on the analytical modeling and design of unbonded posttensioned precast concrete coupling beams. Previous test results from a series of floor-level coupling beam subassembly specimens are compared with the predicted results from a fiber-element analytical model. The test results are also used to validate an idealized coupling beam end moment versus chord rotation relationship that was developed as a design tool following basic principles of equilibrium, compatibility, and constitutive relationships. Based on the experimental and analytical comparisons, the paper presents a seismic design approach to achieve the desired lateral strength, stiffness, ductility, and energy dissipation capacity in unbonded posttensioned precast coupling beams.