Typhoon Damage Analysis of Transmission Towers in Japan

摘要

In the last decade, four strong typhoons have hit the Kyushu area of Japan and inflicted severe damage on power transmission facilities, houses, and so on. Maximum gust speeds exceeding 60m/s were recorded in central Kyushu. Although the wind speeds were very high, the gust factors were over 2.0. However, the meteorological stations have not been located in mountainous areas, creating a deficiency of meteorological station data in the area where the towers were damaged. Since 1995 the authors have operated a network for wind measurement, NeW-MeK, that measures wind speed and direction, segmenting the Kyushu area into high density arrays. Maximum gusts exceeding 70m/s were measured at several NeWMeK sites when Typhoon Bart approached. The gust factors varied widely in southerly winds. The mean speeds increased due to the effect of the local terrain, thus further increasing gust speeds.