On the Rocking Behavior of CLT Wall Assemblies

In the design of buildings in earthquake-prone areas, it is crucial to identify the dissipative regions, namely areas where energy will be dissipated to ensure the structural integrity during a seismic event. It is important to evaluate the number of dissipative elements, their location within the structure and, wherever possible, to assess their mutual interactions in order to foresee their behavior. In CLT structures, connections between adjacent panels in a wall can be designed either to ensure a monolithic behavior of the wall or to be flexible, leading to a coupled behavior of the wall. In the first case, the energy dissipation occurs only in the base connections (hold-downs and angle brackets), whilst in the second case also the panel-to-panel connections contribute to the energy dissipation. In this paper, a formula for the design of wall-to-floor and wall-to-wall connections is proposed. Giving the external loads (axial load and shear load on the wall), the geometry of the wall assembly and the characteristics of the connections involved, the proposed method allows the designer to evaluate the stiffness of the connections between adjacent panels in order to obtain a monolithic or a coupled behavior. This formula has been validated based on the results of experimental tests and numerical analyses.