Factor Analysis of Damage to Small Earth Dams Due to the 1995 Hyogoken-Nambu Earthquake

Damage to small earth dams due to the Hyogoken-Namby Earthquake of January 17, 1995 is discussed. Investigations of 266 dams were conducted in the area where the JMA seismic intensity was 5 or higher, and which were located within about 50 kilometers from the earthquake source fault. Small earth dams suffered various forms of damage such as longitudinal cracking, transverse cracking, settlement and deformation of the dam body. The damage to small earth dams was classified into five grades from no damage to severe damage such as a complete failure. The damage grade was analyzed by several factors such as distance from the fault, topography and geology, intensity of quake motion, direction of dam axis against the fault, year of completion, and height of dam. The characteristics of factors affecting damage to small earth dams were evaluated