Snow Load Effect to Vibration Characteristics of Japanese Traditional Wooden Main Temple Building and Three-Story Pagoda Based on Ambient Vibration and Earthquake Observation Records

Snow load effect to vibration characteristics of Japanese traditional wooden main temple building and three-story pagoda of “Jion-ji”, Japan is studied using ambient vibration measurement and earthquake observation data. The 1st natural frequency of the main temple building ranged from 1.07 to 1.73 Hz in EW and 0.98 to 1.88 Hz in NS. The 1st natural frequency of the pagoda ranged from 1.23 to 1.66 Hz in EW and 1.20 to 1.49 Hz in NS. As a result, vibration characteristics of those heritage structures were affected by snow load distribution on the roof and amplitude of earthquake. In winter, thickly accumulated snow leads to the additional load, having caused the significant change of the vibration characteristics of the structure. The snow load on the natural frequency was as effective as small earthquakes. Large amplitude of strong earthquake is more effective to vibration characteristics of those buildings and decrease the natural frequency. From an earthquake engineering point of view, the equivalent mass of the structure with the snow load in winter was 1.9 times as heavy as that in summer, which indicated seismic safety of the structure would be affected by the snow load in snow area.