ICOLD Bulletin 109, Appendix 1
1 .Presentation
Reported failures are cIassified under the following headings :
Dam category : gravity, arch, buttress and multiple arch, embankment
Cause of failure ; for embankment dams: overtopping during construction, first filling, operation (by overtopping or internaI erosion)
Height (higher/lower than 30 metres)
Dates of failure and construction (pre-/post-1930).
Reservoir capacity, dam length and number of lives lost are also shown where known.
2. Failures
Most reports of failures were taken from ICOLD Bulletin 99 “Dam Failures Statistical Analysis”. However, about twenty of the failures mentioned in the Bulletin were not cIassified, through lack of data or because they were not due to the Irerein classified causes, and 15 of the failures in this Appendix do not appear in Bulletin 99 (mark X).
Many failures of dams of moderate height have probably gone unreported ; very few failures of large dams 10-15m high have been reported, although they represent 20 per cent of ail large dams. In addition, there are few reports on the 700 Japanese dams built before 1930 or the thousands of dams in the non-industrialised countries impounding less than 10 hm3. These three groups together represent one-third of aIl large dams and 5 per cent of reported failures, so that 50 to 100 large-dam failures might have gone unreported.
3. Dam Numbers in Tables
Figures for the number of >30m dams built are reliable.
For <30m dams, there is a large margin ofuncertainty on the number built, mainly
in the height range 10-15m, especially embankment types. The figures in the tables (2 000 pre-1930, 7 000 post-1930) are estimates for 15-30m dams and do not allow for 10-15m structures for which failures do not seem to be generally reported.
Gravity Dams (Concrete or Masonry)/
Barrages-Poids (Béton ou Maçonnerie)
<30 m
400 built before 1930 : 11 failures
1500 built after 1930 : 1 failure
>30 m
350 built before 1930 : 11 failures
1500 built after 1930 : 0 failure
C=Concrete / Béton
M=Masonry / Maçonnerie
U=Upstream dam failure / Rupture du barrage amont
F=Failure dur to flood / Rupture par crue
Arches (First Filling Failure) /
Voûtes (Ruptures au premier remplissage)
Existing Dams
Barrages existants
600>30m / 300<30m
Butresses and Multiple Arches /
Contreforts et Voûtes Multiples
Existing Dams
Barrages existants
200>30m/300<30m
Fill Dams /
Barrages en Remblai
Failure under construction by overtopping (Height and volume are those of the completed dam, not those at the failure time)
( ) gives the height at time of failure, if known
Rupture par submersion pendant la construction (La hauteur et le volume correspondent au barrage terminé)
( ) donne la hauteur lors de la rupture
<30 m
2000 builts before 1930 / 2000 construits avant 1930
7000 built after 1930 / 7000 construits après 1930
>30m
150 built before 1930 / 150 construits avant 1930
2800 built after 1930 / 2800 construits après 1930
E=Earthfill / Terre
R=Rockfill / Enrochement
C=Cofferdam / Batardeau
First Filling of Fill Dams ( by internal erosion) /
Barrages en Remblai – Ruptures au premier remplissage (par érosion interne)
< 30 m
2000 built before 1930 / 2000 construits avant 1930
7000 built after 1930 / 7000 construits après 1930
>30 m
150 built before 1930 / 150 construits avant 1930
2800 built after 1930 / 2800 construits après 1930
*
Fill / Remblai :
E = Earthfill / Terre
R = Rockfill / Enrochement
Foundation / Fondation :
S = Soft / Meuble
R = Rock / Rocher
Failure in Operation of Fill Dams (by internal erosion) /
Barrages en Remblai – Rupture en service (par érosion interne)
< 30 m
2000 built before 1930 / 2000 construits avant 1930
7000 built after 1930 / 7000 construits après 1930
Failure in Operation of Fill Dams (by internal erosion) /
Barrages en Remblai – Rupture en service (par érosion interne)
> 30 m
150 built before 1930 / 150 construits avant 1930
2800 built after 1930 / 2800 construits après 1930
* Fill / Remblai
E = Earthfill / Terre
R = Rockfill / Enrochement
Foundation / Fondation
S = Soft / Meuble
R = Rock / Rocher
Fill Dams / Barrages en Remblai
Failures in operation by overtopping / Ruptures en service par submersion
>30 m
150 built before 1930 / 150 construits avant 1930
2800 built after 1930 / 2800 construits après 1930
E = Earthfill / Terre
R = Rockfill / Enrochement
U = Failure of Upstream Dam / Rupture de barrage amont
G = Jamming of Gates / Non-fonctionnement des vannes
S = Spillway defect / Défaillance du déversoir
Fill Dams / Barrages en Remblai
Failures in operation by overtopping / Ruptures en service par submersion
<30 m
2000 built before 1930 / 2000 construits avant 1930
7000 built after 1930 / 7000 construits après 1930
E = Earthfill / Terre
R = Rockfill / Enrochement
U = Failure of Upstream Dam / Rupture de barrage amont
G = Jamming of Gates / Non-fonctionnement des vannes
S = Spillway defect / Défaillance du déversoir
Fill Dams / Barrages en Remblai
Failures in operation by overtopping / Ruptures en service par submersion
<30 m
2000 built before 1930 / 2000 construits avant 1930
7000 built after 1930 / 7000 construits après 1930
G = Gates Jamming / Non-fonctionnement des vannes
U = Upstream dam Failure / Rupture de barrage amont
S = Spillway defect / Défaillance du déversoir
E = Earthfill / Terre
R = Rockfill / Enrochement