Direct Displacement-Based Seismic Design of Unbonded Post-Tensioned Masonry Walls

摘要

Post-tensioned masonry walls exhibit desirable seismic performance characteristics due to increased in-plane strength and the absence of residual lateral displacement at the conclusion of seismic loading. The direct displacement-based design (DDBD) approach aims to provide a method whereby a structure may be designed to achieve a predefined level of lateral deformation under a predefined level of earthquake intensity. This paper details the development of a DDBD procedure to assist in the design of unbonded post-tensioned masonry structural walls. The level of initial tendon prestress is shown to have a significant effect on wall response and guidance is provided for making this design choice. An acceptable correlation is demonstrated when the results from the method are compared with actual data obtained from previous shake table testing of three full-scale concrete masonry walls. The paper concludes by presenting a design example that highlights the steps involved in applying this approach to an actual wall structure and demonstrates the simplicity of the method.