SEISMIC DAMAGE TO IRRIGATION AND DRAINAGE FACILITIES ON NIIGATA ALLUVIAL PLAIN

[摘要] The authors have investigated the damage caused by the Niigata earthquake to irrigation and drainage facilities. Since the damage was very serious and many data were available about geology and soils of Niigata Plain, their investigation was conducted in search for relationship between damage and soil conditions on the plain.The ground was found heavily ruptured and both fields and facilities badly damaged on some old river sites, but practically no ground rupture was seen on flood plains where soils are of silt, clay and peat. A heavily cracked zone was traced in the aerial photographs of the Tsusen River district in which damage was most serious, and it was found that loose sands of about 5 m, covered with clayey peat less than 2 m in thickness were common in the soil profiles of the zone.No or very slight damage was done to main structures of large pumping plants, and almost nothing was damaged on the dunes.

[学科分类] 建筑学