Safety Standard for Special Class Damslopes Based on Reliability Analysis
Table 4
Definition of special class structures.
Classes
Definition
Annual failure probability
βa
Special class 1
The flood caused by the dam failure will cause a class 1 dam downstream to collapse, even with an effective early warning
10–8
4.70
Dams with a height exceeding 250 m and a capacity exceeding 1 × 109 m3
Special class 2
The flood caused by the dam failure will not cause a class 1 dam downstream to collapse with an effective early warning but will cause it to collapse with an ineffective early warning
5 × 10−8
4.45
The flood caused by the dam failure will cause a class 2 dam downstream to collapse even with an effective early warning
Dams with heights in the range of 200–250 m and a capacity exceeding 1 × 109 m3
