Seismic performance of energy-dissipating post-tensioned CLT shear wall structures I: Shear wall modeling and design procedure

Abstract

This work described herein was conducted within performance-based seismic assessment framework on post-tensioned (PT) CLT shear wall structures with UFP dissipaters (PT-Strs-U) and that with friction dissipaters (PT-Strs-F). In this paper (Part I of this work), a modeling method for the predictive models of post-tensioned CLT shear walls with either UFP dissipaters (PT-Walls-U) or friction dissipaters (PT-Walls-F) was developed. Furthermore, based on both the calibrated dissipater model and the predictive shear wall model, a design procedure for the energy-dissipating PT CLT shear walls was also proposed. Given a target shear wall performance, it will be able to determine the required mechanical properties of the dissipaters. With this design procedure, systematic parametric analysis on both the PT-Walls-U and the PT-Walls-F was conducted, while changing the variables (i.e., initial post-tensioning force, nominal strand diameters, and wall height-to-width ratios). The analytical performance of each shear wall and the required mechanical properties of the adopted dissipaters were respectively obtained. Finally, the equations for the wall capacity estimation were also provided. The calibrated PT-only CLT shear wall model and the dissipater model can be used to estimate the hysteretic curve of the corresponding energy-dissipating PT CLT shear wall based on the aforementioned predictive model. The enhancement of the shear wall capacity is more significant with an increase of the initial PT force or the wall height-to-width ratio compared to an increase of the strand diameter. The equation-based shear wall capacity is in agreement with the analytical shear wall capacity from the predictive model. Overall, the predictive model of the energy-dissipating PT CLT shear walls and the proposed design procedure have led to reliable and valuable data for both the wall capacity and the required dissipater properties. They will be used for designing and modeling the energy-dissipating PT CLT shear wall structures conducted in the Part II of this work.