FLOOD06195

• County: Statewide
• Community: State of Colorado
• Basin: Statewide
• Title: Measurment of Peak Discharge at Culverts by Indirect Methods
• Date: 6/1/1968
• Prepared By: G.L. Bodhaine
• Floodplain - Doc Type: Educational/Technical/Reference Information

e

e

e-

MEASUREMENT OF PEAK D15CHARGE AT CULVERTS BY INDIRECT METHODS 39

multiplying the coefficient for the square.ended
pipe by an adjustment factor, k, or kw. These
adjustment factors are a function of the degree
of entrance' rounding or beveling and these
relations, applicable to flow types 1, 2, and 3,
are defined in figures 21 and 22.

Machine tongue-and-groove reinforced con-
crete pipe from 18 to 36 inches in diameter has
been tested, and no systematic variation was
found between the discharge coefficient and the
headwater.diameter ratio. wiD varied from
0.06 to 0.08, and 9 averaged 780 with small

1.00

v

Use 0.93 for ratios <0.4

UJ
"
0:
~ 0.90
u
!!!
o
...
o
I-
Z
UJ 0,80
U
u:
...
UJ
o
u

Pipe culvert having square entrance

01 1,1 I,S-
0,70
0,4 0,6 0,8 1.0 1.2 1.4 1.6
RATIO OF HEADWATER TO PIPE DIAMETER, (Ih'ozy
---.~-_.::'>

Figure 20.-Base coefficient of discharge for types 1, 2, and 3 flow in pipe culverts with square entrance mounted
flush with vertical headwall.

1.20

1.15

..IJt.... 1.10

1.05

1.00
o

0,04

0.06

0,02

r r
-or-
b D

-r0%
~-~~

0,08

0,14

0,10

Figure 21.-Varialion of the discharge coefficient with entrance rounding, types 1,2, and 3 flow in box or pipe
culverts set flush with vertice I headwall.