An Analytical Method to Reproduce Seismic Behavior of a Two-Story Cross-Laminated Timber Building at Large Deformation

Understanding the seismic resistance mechanisms and safety limits of cross-laminated timber (CLT) buildings and performing an accurate evaluation of their seismic performance is critical in earthquake-prone areas such as Japan, the US, and Italy to ensure that human lives are protected against major earthquakes. However, the knowledge from shaking table tests of full-scale CLT buildings is limited, and most tests’ maximum interstory drift is less than 4%. As a first step toward collapse analysis, this study replicated a full-scale two-story shake table experiment with a maximum interstory drift of 8.77%. The analysis software was developed by the authors and modified to consider the restoring force and the P–δ effect to replicate seismic behavior at large deformation. The skeleton curve parameters were employed in the analysis model and then changed. The results that matched the experimental results well were searched comprehensively by performing data assimilation. As a result, both the overall behavior (story shear force–interstory drift relationship) and the detailed behavior (uplift displacement of CLT wall foot of the first story) were consistent with the experimental results, indicating that the proposed analytical method can replicate the seismic behavior of CLT buildings even at large deformation

Seismic Response Comparison of Full-Scale Moment-Resisting Timber Frame and Joint Test Result

This paper presents the seismic performance of the moment-resisting timber frame (MRTF). In Japanese urban areas, there are many urban small houses, and it is difficult to design a wooden building to ensure both the seismic performance and the comfortable plan that effectively makes use of small and constrained sites, and it also lacks flexibility in the design. Therefore, expectations are rising for high performance of MRTF using residential members. In this study, to clarify the seismic performance and the dynamic behavior under the heavy seismic wave, we conducted a full-shaking table test of the 2-story MRTF composed of residential members with short sides. The structure was designed by the allowable stress design (ASD) to resist 1.5 times the earthquake ground motion required in Japanese Building Standard Law (BSL) and linear analysis under frequent loading conditions (snow, wind, and earthquake events corresponding to a return period of approximately 50 years), and the unidirectional full-scale shaking table tests were conducted. The structure did not collapse up to a peak ground acceleration of 0.87 g and experienced ∼1/20 rad of maximum interstory drift. This indicates that an MRTF designed by the method can secure the seismic performance for a large earthquake. The time-response analysis was also conducted based on the joint tests, but the stiffness of the analytical result is little lower than the experimental result. Then, we tried the parameter identification using quality engineering to reproduce the experimental behavior. The results indicated that the moment resistance of the joint was higher because of the stressed-skin effect of the floor

Experimental Behavior of L-Shaped and T-Shaped Cross-Laminated Timber to Evaluate Shear Walls with Openings

There is increasing interest in using cross-laminated timber (CLT) in buildings because of its high strength and stiffness. In Japan, structural design guidelines for CLT buildings were established in 2016 and construction of mid-rise buildings is increasing. Wide-panel walls can exceed widths of 10 m and integrate cut-outs for window and door openings. However, under lateral loads, corner cracks at the openings have been the most prevalent failure mechanism. To investigate the initiation and propagation of corner cracks, a series of bendings are undertaken on L- and T-shape specimens extracted from the CLT panels. In addition, three-point bending and shear tests are also carried out on beam sections extracted from the CLT panels. Three types of brittle failure were observed: bending failure of the beam or column, and rolling shear failure

Seismic Response Comparison of Full-Scale Moment-Resisting Timber Frame and Joint Test Result

This paper presents the seismic performance of the moment-resisting timber frame (MRTF). In Japanese urban areas, there are many urban small houses, and it is difficult to design a wooden building to ensure both the seismic performance and the comfortable plan that effectively makes use of small and constrained sites, and it also lacks flexibility in the design. Therefore, expectations are rising for high performance of MRTF using residential members. In this study, to clarify the seismic performance and the dynamic behavior under the heavy seismic wave, we conducted a full-shaking table test of the 2-story MRTF composed of residential members with short sides. The structure was designed by the allowable stress design (ASD) to resist 1.5 times the earthquake ground motion required in Japanese Building Standard Law (BSL) and linear analysis under frequent loading conditions (snow, wind, and earthquake events corresponding to a return period of approximately 50 years), and the unidirectional full-scale shaking table tests were conducted. The structure did not collapse up to a peak ground acceleration of 0.87 g and experienced ∼1/20 rad of maximum interstory drift. This indicates that an MRTF designed by the method can secure the seismic performance for a large earthquake. The time-response analysis was also conducted based on the joint tests, but the stiffness of the analytical result is little lower than the experimental result. Then, we tried the parameter identification using quality engineering to reproduce the experimental behavior. The results indicated that the moment resistance of the joint was higher because of the stressed-skin effect of the floor

An Analytical Method to Reproduce Seismic Behavior of a Two-Story Cross-Laminated Timber Building at Large Deformation

Understanding the seismic resistance mechanisms and safety limits of cross-laminated timber (CLT) buildings and performing an accurate evaluation of their seismic performance is critical in earthquake-prone areas such as Japan, the US, and Italy to ensure that human lives are protected against major earthquakes. However, the knowledge from shaking table tests of full-scale CLT buildings is limited, and most tests’ maximum interstory drift is less than 4%. As a first step toward collapse analysis, this study replicated a full-scale two-story shake table experiment with a maximum interstory drift of 8.77%. The analysis software was developed by the authors and modified to consider the restoring force and the P–δ effect to replicate seismic behavior at large deformation. The skeleton curve parameters were employed in the analysis model and then changed. The results that matched the experimental results well were searched comprehensively by performing data assimilation. As a result, both the overall behavior (story shear force–interstory drift relationship) and the detailed behavior (uplift displacement of CLT wall foot of the first story) were consistent with the experimental results, indicating that the proposed analytical method can replicate the seismic behavior of CLT buildings even at large deformation

Experimental Behavior of L-Shaped and T-Shaped Cross-Laminated Timber to Evaluate Shear Walls with Openings

There is increasing interest in using cross-laminated timber (CLT) in buildings because of its high strength and stiffness. In Japan, structural design guidelines for CLT buildings were established in 2016 and construction of mid-rise buildings is increasing. Wide-panel walls can exceed widths of 10 m and integrate cut-outs for window and door openings. However, under lateral loads, corner cracks at the openings have been the most prevalent failure mechanism. To investigate the initiation and propagation of corner cracks, a series of bendings are undertaken on L- and T-shape specimens extracted from the CLT panels. In addition, three-point bending and shear tests are also carried out on beam sections extracted from the CLT panels. Three types of brittle failure were observed: bending failure of the beam or column, and rolling shear failure