INGENIEUR
Figure 8 - Locations of Identified Risk Factors for Level 2 Risk Assessment
Table 1 – Risk Factors Identified for Level 2 Risk Assessment
R1
R2
R3
R4
R5
R6
6
56
Piping at old river course due
to arching effect at the filled
embankment Ch400.
Excessive settlement resulting in
cracks at the dam embankment due
to thermally altered granite at the dam
foundation Ch350 to ch950m.
Piping at the left abutment might
lead to blow out at Weng Lee Quarry
face due to layer of whitish thermally
altered granite.
Cut slope instability at draw off tower
No.2.
Ch.1750 Piping through the left
abutment at the existing dam due to
layer of a porous weathered granite.
Piping of the existing dam during
construction of raising existing dam
due to excavation at the toe of dam.
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R7
R8
Risk of collapse of the existing dam during
trenching for the construction of a plastic
concrete cut off wall.
Piping through the clay core of the dam
embankment due to a low stress zone
along draw off culvert.
R9 Slope instability at the inlet channel of the
spillway.
R10 Impact of rock blasting at the Weng Lee
Quarry on the integrity of plastic concrete
walls and the grout curtain of dam.
Slope instability of hills at the reservoir
rim during the operational stage.
R11
R12 Instability of the Tunnel Inlet Portal during
construction.
R13 Instability of the Access Bridge to the
Draw-off Tower No 1.