Civil Engineering Reference
In-Depth Information
Base-of-rail
Area,
A
, required
for
Q
d
Datum
High water level for
Q
L
b
Δ
h
d
u
d
d
Datum
FIGURE 3.2
River crossing profile with constriction at
Q
.
of the new channel cross section at the constriction. It can be shown that the coefficient
of contraction,
C
c
, depends on the following:
• Contraction ratio
• Constriction edge geometry and angularity
• Submerged depth of abutment
• Slope of abutment face
• Eccentricity of the constriction relative to normal stream flow
• Froude number, which is
Q
A
√
gd
,
F
=
(3.6)
