STUDY ON RELATIONSHIP BETWEEN ROOF SNOW SLIDING AND SEISMIC RESPONSE OF WOOD-FRAME HOUSES BY SEISMIC RESPONSE ANALYSIS

To clarify relationship between roof snow sliding and seismic response of wood-frame houses, the authors examined seismic performance of the houses by elasto-plastic seismic response analysis. At first, hysteresis characteristics that reflected sliding of roof snow on flat roof and gable roof was evaluated by comparison with the previous shaking table test by the authors. The response acceleration, velocity and displacement of the structure and roof snow calculated by the seismic response analysis using the hysteresis characteristics were similar with the results that were observed in the test. Next, two-story houses that were designed not only for seismic action but also snow load were analyzed by using above mentioned hysteresis characteristics. Ground acceleration records observed in El Centro, Hachinohe, Kobe, Kawaguchi and Kashiwazaki etc were used in the analysis. The maximum response displacement calculated by the analysis was compared with design safety limit displacement of the wooden structure. As the result, when roof snow sliding occurred in flat roof or gable roof, it was estimated that the response displacement was smaller than design safety limit displacement even with snow load of 1.5 to 6.0 kN/m2.