Long-term performance of post-tensioned cross-laminated timber (CLT) shear walls: hygro-mechanical model validation and parametric analysis

Post-tensioned cross-laminated timber (CLT) shear wall structure is an innovative solution of earthquake resilient structures. The prestressing force of post-tensioned CLT shear walls remarkably affect the structural seismic performance. Due to the time-dependent elastic, creep, and environmental deformation of wood, the prestressing force will change over the service life of the structure. In this study, a hygro-mechanical numerical model for simulating the time-dependent performance of post-tensioned CLT shear walls was established. Moisture diffusion analysis, time-dependent deformation calculation and prestressing force updating were incorporated in the proposed model, which was further validated based on experimental results. Subsequently, a series of parametric analysis was conducted to study the effect of various material properties, geometric characteristics, environmental conditions and prestressing forces on the long-term performance of post-tensioned CLT shear walls. The analytical results of the key parameters such as the CLT shear wall dimension, the initial prestressing force, and the environmental temperature and relative humidity were presented and discussed. Practical suggestions for enhancing the long-term safety of post-tensioned CLT shear wall structures were proposed.