Experimental seismic behaviour of a two-storey CLT platform building: Design and shake table testing

Since its introduction in Europe more than two decades ago, Cross Laminated Timber (CLT) is viewed as a new generation of engineered wood products and has found its way into the US construction market. Recent research efforts have demonstrated that CLT can be effectively utilized as a seismic force resisting system. This paper presents the results of part of a study conducted at Colorado State University to systematically investigate seismic behaviour of CLT shear wall systems in regions of high seismicity for use in the United States. Specifically, the results of a full-scale shake table test of a two-storey 223 m2 building. The CLT special shear walls in the building were designed based on a design methodology that resulted from connector and reverse cyclic testing of isolated CLT shear walls using a generic connector. The main design assumption for these walls is that all overturning was resisted by the overturning anchor (tie-down rod or hold-downs) at the wall ends and the shear is resisted by the generic angle brackets connected with nails. The shake table tests were performed in three phases with each phase consisting of a different CLT wall configuration. Phase 1 and 2 were multi-panel configurations with 4:1 (h/b) and 2:1 aspect ratio panels, respectively. Phase 3 was another 4:1 aspect ratio wall with return walls added in the transverse direction to examine their effect on the overall response. The structure was subjected to several ground motions including one scaled to the maximum credible earthquake (MCE), equivalent to a 2475 year return period.