An innovative connection system for platform-type mass timber buildings

Platform-style construction is a widely recognized and well-established approach among engineers and developers for multi-story mass timber buildings. This construction method offers many advantages, such as rapid assembly, an excellent strength-to-weight ratio, and appealing aesthetic features. In a platform-type construction, each story is constructed by placing the floor panels on top of the load-bearing wall, creating a platform for the level above. Although this method offers numerous advantages, recent research findings have revealed that cross-laminated (CLT) platform buildings with conventional connections, such as wall-to-floor hold-down brackets and shear connectors with nails and screws, are prone to experience a high degree of damage under design-level earthquakes. Consequently, conventional connections in platform-type construction are vulnerable to more damage under aftershocks and do not meet the damage avoidance requirements of seismic design. This paper introduces an innovative floor-to-wall connection for a platform-type low-rise mass timber building that mitigates the limitations of conventional connections. The effectiveness of the proposed connection has been investigated, and the seismic performance of the system, which incorporates the proposed connection, has been outlined in this paper. A numerical model with an innovative inter-story isolation system is developed in ETABS, and the seismic performance of the isolated structure was evaluated using Response Spectrum Analysis (RSA) and Nonlinear Time History Analysis (NLTHA). This study revealed that inter-story isolation systems significantly reduced the seismic demands on the mass timber components, demonstrating the system's ability to dissipate seismic energy. Additionally, the system displayed effective energy dissipation while exhibiting self-centering behaviour.