Non-Dimensional Design Procedures for Precast, Prestressed Concrete Hybrid Frames

Abstract

The precast, prestressed concrete hybrid frame system offers an important feature that allows the elimination of residual drift after an earthquake. The existing design process for hybrid frames includes an iterative, step-by-step procedure. The objective of this research is to develop a non-iterative, simplified design procedure for precast concrete hybrid frames. A set of new non-dimensional parameters and procedures for the design of precast concrete hybrid frames has been developed. A fracture criterion for the mild steel reinforcing bars that considers low-cycle fatigue under combined axial and bending strains is proposed. Parametric studies were performed using the developed non-dimensional procedure. These optimization studies aimed to achieve zero residual drift while the moment capacity of the section is equal to the applied design moment. The results of these studies were used to generate non-dimensional design charts and equations. An example using the new procedures is presented in detail in Appendix B. The results using conventional procedures and the proposed design charts and design equations are compared.