42
4 Historic Failures “Statistics”
Fig. 4.3 Functional scheme of the e-IDC with the hazards selected for this study
In Fig. 4.3 we identify four different functions for the e-IDC—geotechnical investigations, engineering, construction, and monitoring, management and water balance—constituting the chain of elements responsible for success/failure of a dam.
Various hazards lurking within each element—for example: insufficient effort,
mistakes, excessive audacity, etc.—leading to a probability of failure p f for each
element evaluated using a reliability model (Eqs. 4.1, 4.2) The chained elements
can then be evaluated using, again, a reliability model (series, Eq. 4.1) in the case
depicted in Fig. 4.3). The list of selected hazards should be discussed project by
project.
Modes of failure previously identified in the literature [e.g. by United Nations
Environmental Protection (UNEP); International Commission On Dams (ICOLD);
World Information Service of Energy (WISE); Commission On Large Dams
(USCOLD) and United States Environmental Protection Agency (USEPA)] due to
the hazards selected in Fig. 4.3 are (Fig. 4.4):
Over-topping Slope Instability Earthquake
FoundaƟon
Seepage
Structural
Erosion
Mine Subsidence Unknown
0
5
10
15
20
25
Cause of Failures (from USCOLD, 1994)
No. of Dam Failures
Fig. 4.4 Dam failures versus cause of failure. From USCOLD 1994
4 Historic Failures “Statistics”
Fig. 4.3 Functional scheme of the e-IDC with the hazards selected for this study
In Fig. 4.3 we identify four different functions for the e-IDC—geotechnical investigations, engineering, construction, and monitoring, management and water balance—constituting the chain of elements responsible for success/failure of a dam.
Various hazards lurking within each element—for example: insufficient effort,
mistakes, excessive audacity, etc.—leading to a probability of failure p f for each
element evaluated using a reliability model (Eqs. 4.1, 4.2) The chained elements
can then be evaluated using, again, a reliability model (series, Eq. 4.1) in the case
depicted in Fig. 4.3). The list of selected hazards should be discussed project by
project.
Modes of failure previously identified in the literature [e.g. by United Nations
Environmental Protection (UNEP); International Commission On Dams (ICOLD);
World Information Service of Energy (WISE); Commission On Large Dams
(USCOLD) and United States Environmental Protection Agency (USEPA)] due to
the hazards selected in Fig. 4.3 are (Fig. 4.4):
Over-topping Slope Instability Earthquake
FoundaƟon
Seepage
Structural
Erosion
Mine Subsidence Unknown
0
5
10
15
20
25
Cause of Failures (from USCOLD, 1994)
No. of Dam Failures
Fig. 4.4 Dam failures versus cause of failure. From USCOLD 1994