The characterization and monitoring of buildings is an issue that has attracted the interest of many sectors over the last two decades. With the increasing use of permanent, continuous and real-time networks, ambient vibrations can provide a simple tool for the identification of dynamic building parameters. This study is focused on the long-term variation of frequency and damping in several buildings, using the Random Decrement Technique (RDT). RDT provides a fast, robust and accurate long-term analysis and improves the reliability of frequency and damping measurements for structural health monitoring. This reveals particularly useful information in finding out precisely how far changes in modal parameters can be related to changes in physical properties. This paper highlights the reversible changes of the structure's dynamic parameters, correlated with external forces, such as temperature and exposure to the sun. Contrasting behaviors are observed, including correlation and anti-correlation with temperature variations.

This study develops an analytical model to describe the behaviour of multi-storey multi-panel CLT shearwalls, specifically accounting for cumulative loads between storeys and the effect of the diaphragm. The analysis considers the contribution of hold-downs, wall-to-floor connections, and panel-to-panel joints, as well as loads transferred from storeys above. The analysis has been developed for shearwalls acting as a series of coupled panels (CP) each individually rotating about a corner. Force transfer between storeys is implemented by distributing reactions through the upper floor diaphragm and a direct force from the upper storey's hold-down. Structuring the equations this way allows for a simplified formulation while including several components of the system's complex behaviour. Two-dimensional finite element modelling is used to verify the accuracy of the developed model.