Seismic Response Characteristics of Wooden Houses Using Rocking Pillars

A common failure mode for wooden houses in Japan during major earthquakes is a total structural collapse initiated by the failure of the first story. One method to improve seismic performance is the installation of rigid, continuous column-like members known as rocking pillars. These high-rigidity pillars help to homogenize the inter-story drift between floors, allowing surplus seismic capacity from the upper story to be redistributed throughout the entire structure. This study verifies the effectiveness of rocking pillars through shaking table experiments on a 1/4 scale, two-story wooden house model. The model was subjected to repeated seismic input until story collapse. The results demonstrated that the model without rocking pillars exhibited a progressively larger response in the first story, leading to its eventual collapse. In contrast, the model equipped with rocking pillars showed a significantly suppressed response and a markedly reduced risk of collapse, confirming their collapse-prevention capabilities.