FLOOD09199

• County: Statewide
• Basin: Statewide
• Title: HEC-2 Water Surface Profiles - Users Manual
• Date: 11/1/1976
• Prepared For: US
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Educational/Technical/Reference Information

EXHIBIT 4

REQUIRED CROSS SECTIONS FOR NORMAL BRIDGE ROUTINE

The cross sections below show the points required on cards GR when using
the normal bridge routine. Cross sections 1, 2, 7, 8 describe the natural
river channel. Cross sections} and 6 are adjacent to the bridge on the
downstream and upstream sides respectively and include elevations and
stations of an artificial levee. whose top is approximately equal to the.
low chord elevation (ELLC) and top of roadway elevation (ELTRD) respectively.
The artificial levee is included in the cross section points to confine the
flow to the channel area (bridge area) when the water flows under the low
chord, and to allow the overbank area to be used for flows over the roadway.
The left and right bank stations must be equal to the station at the top
of the artificial levees.

ELLC+ (Section 3)
~RD:t (Section 6)

L/~ ~J
I ~ I \

'U

top

"[''''..''

-0- ..... Low chord
points

+- Ground
points

Cross Sections 1, 2, 7, 8
Full natural cross sections

Cross Sections 3 and 6
Immediately downstream
and upstream of bridge
embankment.

Cross Sections
4 and 5
within bridge

8

~
Sif-

o'!

L

I

2
1>
I

3

4

5

6

7
,'0

Variable IEARA on card X3 must equal 10 for cross
sections 4 and 5 are within the bridge and BT (or
describe the low chord and top or roadway points.
the BT cards should also appear on the GR cards.

sections 3 and 6.
X2) cards are used
All stations used

Cross
to
on

.
The points defining the artificial levee can be omitted if the elevations
where the effective area changes are shown on the X3 cards (eighth and ninth
fields). Thus cross sections 3 and 6 could resemble cross sections 2 and 7.

Exhibit 4