نمونه متن انگلیسی مقاله
A dam may fail when the loading exceeds the resistance against overtopping, internal erosion, slope instability, sliding/overturning, excessive deformation etc. To investigate the causes of failures, it is necessary to study characteristics of the dams which have experienced failures. In this work, more than 1600 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 make up 66% of the 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: homogeneous earthfill dams, zoned earthfill dams, earthfill dams with corewalls, and concrete faced earthfill dams. Further analysis of the failure modes and causes of the four types of earth dams is carried out. Potential locations at risk are also described to provide the reader with a better understanding of earth dam failures.
In recent years, dam safety has drawn increasing attention from the public. This is because floods resulting from dam failures can lead to catastrophic loss of life and property, especially in densely populated areas. For instance, the breaching of the 62 dams in Henan Province of China in August 1975 during an extreme storm caused a regional death count of about 26,000 (Ru and Niu 2001). A robust understanding of the characteristics of dam failures is of critical importance to dam risk mitigation. In this paper, the failure of a dam is identified according to the following definitions of failures type 1 and type 2 by the International Commission on Large Dams (ICOLD) (1974). Failure type 1 is a major failure involving the complete abandonment of the dam while failure type 2 is a failure that at the time may have been severe but has since been successfully repaired and the dam has again been brought into use.