Non-dimensional design charts for unbonded, post-tensioned, split precast concrete walls

Abstract

The Precast Seismic Structural Systems (PRESSS) research proposed five different seismic structural systems made from precast concrete elements. These systems formed various parts of the structural framing in the PRESSS phase III building that was tested at the University of California at San Diego. Based on the PRESSS evaluation, one of the structural systems that has the potential to eliminate residual drift after an earthquake was the unbonded, post-tensioned, split precast concrete wall system. The PRESSS report outlines a dimensional design procedure for the unbonded post-tensioned split precast concrete walls. This procedure is iterative, requiring lengthy calculations to achieve an optimum design. This study developed a set of new nondimensional parameters and procedures for the design of such walls. The goal of this research was to develop a set of nondimensional design charts that require no iterations. Such charts are based on an optimum design of zero residual drift while the moment capacity of the wall is equal to the applied design moment. The results of these studies were used to generate nondimensional design charts. A numerical design example using the conventional iterative PRESSS design procedure and the new noniterative design charts procedure is presented, and the methods are compared.