HGE 5 - Dams

Notes

Vertical Forces

Wc= unit wt of concrete (area)

Fv= 9.81(Area of water on top of the dam)

Horizontal Forces

Fh= 0.5(gamma off water)((height of water)²

Resultant Forces

.

Moments

.

Factor of Safety Indication

F.S. > 1 - Safe

F.S. = 1 - Critical

F.S. < 1 - Unsafe

Factor of Safety against Overturning

Factor of Safety against Sliding

Location of x̄

Eccentricity “e”

Foundation Pressure (If e ≤ B/6)

Ry is located inside the middle 3rds (B/3)

B - width of dam

Foundation Pressure (If e > B/6)

Ry is located outside the middle 3rds (B/3)

s = x̄

Shearing Stress

𝜏 = v / A = F_h / B ^_x W
F_h = horizontal hydrostatic force
B - base width
W - perpendicular length (assume 1)

Hydrostatic Uplift ‘‘U‘‘

U = ½(γ_w)(h)(B^_XW)(u%)

γ_w - unit weight of water
h - head of water
B - base width
W - perpendicular length (assume 1)
u% - hydrostatic uplift