Seismic Performance of Three-Story Cross-Laminated Timber Structures in Japan

Abstract

To promote the development of cross-laminated timber (CLT) structures, the Japanese Government Notifications on Structural Design of CLT Buildings (GN 611) was issued in 2016. In GN 611, three types of platform-framing CLT structures were classified in the simple calculation method of Route-1. Compared with a platform-framing structure, which has been clarified in GN 611, a balloon-framing structure is superior in shortening the construction period and reducing the number of CLT panels and metal connectors. To study the seismic properties of balloon-framing CLT structures and develop new structures for a CLT building, four full-scale, 3-story CLT structures were tested under quasi-static cyclic loading: Specimen 1 was a platform-framing structure with narrow wall panels; Specimen 2 was a balloon-framing structure with continuous wall panels; Specimen 3 a was platform-framing structure with wide wall panels; and Specimen 4 was a balloon-framing structure with continuous wall panels and glulam beams. In this study, experiments were conducted, and the seismic performance of the balloon- and platform-framing CLT structures were evaluated and compared. The test results indicated that the seismic properties of Specimens 1, 2, and 3 were similar and that the design method of Specimen 1, as specified in GN 611, was applicable for Specimens 2 and 3. Specimen 4 exhibited higher lateral load resistance than the other three specimens. The performance of Specimen 4 depended on the moment-resisting performance of the glulam beam and CLT wall joint. In this case, the moment-resisting performance obtained through the experiment was significantly higher than the predicted performance.