Questionnaire survey of the occupants of high-rise residential buildings in Sapporo after the 2018 Hokkaido Eastern Iburi Earthquake

In this study, a resident questionnaire survey was conducted for three reinforced-concrete high-rise condominium buildings in Sapporo. All three were subjected to the 2018 Hokkaido Eastern Iburi Earthquake. Resident experiences of shaking and damage due to the earthquake, the seismic measures taken before and after the earthquake, and conditions during the long-term blackout were evaluated by the survey. Resident anxiety and their difficulty in taking actions due to the shaking were relatively small, because the ground motions input to the buildings were not very large. The long-term power outage due to the earthquake had a great impact on the occupants. Particularly, the inability to use elevators caused a great inconvenience to the residents of higher floors, making it difficult for them to leave their dwelling units. Each of the three buildings was equipped with an emergency power supply; however, differences in the operation methods of these supplies affected the convenience of the occupants during the power outage. The inconvenience and anxiety caused by the shaking and the power outage left a strong impression on the residents. This may have resulted in motivation to make further earthquake preparations, such as stockpiling of flashlights, lanterns, food, and water, after the complex disaster