Analysis of earth dam failures - A database approach

A dam may fail when the loading (overtopping flood, flow through or beneath the dam, earthquake or blasting loading, terrorist attacks, deterioration etc.) exceeds the resistance against overtopping, internal erosion, slope instability, sliding/overturning, excessive deformation etc. To properly describe the causes of dam failures, it is necessary to study characteristics of the dams which have experienced failures. In this work, more than 900 dam failure cases throughout the world excluding China are compiled into a database, including details of the dams, the reservoirs, the triggers, and the failures. This paper focuses on failure of earth dams, which makes up 66% of the whole failure cases in the database. A statistical analysis of the failure characteristics is conducted. According to dam zoning and corewalls, earth dams are divided into four typical categories: (1) homogeneous earthfill dams, (2) zoned earthfill dams, (3) earthfill dams with corewalls, and (4) concrete faced earthfill dams. Further analysis of the failure modes and causes of these subdivided earth dams is carried out. Potential locations at risk are also described to provide the reader with a better understanding of earth dam failures.