Environmental Engineering Reference
In-Depth Information
- Damage to a spillway;
- Damage to a saddle dam or its foundations;
-Partial or complete blockage of the storage, where this is narrow, to form a landslide
dam (or the perceived potential for this to occur). Flooding upstream and overtop-
ping and eventual failure of this landslide dam are further possible consequences.
Failures of such dams can be disastrous (Schuster & Costa 1986, and King et al., 1987;
1989), or
-
Generation of a large, destructive wave by rapid sliding into the reservoir, such as that
which overtopped Vaiont Dam in Italy in 1963, and claimed 2600 lives (Hendron &
Patton, 1985; Muller 1964, 1968; Kiersch 1965).
Mass with potential to slide
(pre-existing landslide)
Water table after
filling the storage
Full supply level
Minimum operating level
Water table before
filling the storage
Figure 2.42. Effect of filling and operating a storage at the narrow base of a deep, steep-sided valley.
Mass with potential to slide
(a)
Water table before
filling the storage
Mass with potential to slide
Full supply level
(b)
Water table after
filling the storage
Figure 2.43. Effect of filling a storage, on the stability of a low, narrow part of its rim, formed by jointed
rock (a) Before filling the storage (b) After filling the storage.
