Performance of a 2-Story CLT House Subjected to Lateral Loads

Abstract

A 2-story full-scale model of a cross-laminated timber (CLT) house was tested under quasi-static monotonic and cyclic loading. The primary objectives were to investigate 3D system performance of a CLT structure subjected to lateral loads in terms of lateral strength and deformability capacity, global behavior of the structure, frequency response of the structure before and after each test, and performance of anchoring connectors (hold-downs, brackets) and connections between CLT panels. The house was 6.0×4.8 m in plan with a height of 4.8 m. A total of five (one push-over and four cyclic) quasi-static tests were performed, one direction at a time. Parameters, such as the direction of loading, number of hold-downs, and number of screws in perpendicular wall-to-wall connections, were varied in the tests. The CLT structure performed according to the design objectives, with the ultimate resistance being almost identical in both directions. Failure mechanisms, i.e., shear failure of nails in the brackets in the first story as a result of sliding and rocking of the CLT wall panels, were similar in all tests. Even after the maximum force was reached, no global instabilities of the house were detected. Torsion effects did not compromise the integrity, stability, or the lateral resistance of the building. The outcomes of the full-scale CLT house tests will be used for further analytical and numerical analyses to help the implementation of CLT as a structural system in the North American building codes and material standards.