Bed Elevation (m)
127
126
125
124
123
122
121
120
Mile 18
119
Mile 17
Mile 16
Boom
300 m
Figure 19. Bed elevation in the vicinity of the slant-oriented boom at RM 16.
solve the hydrodynamic equations. Ice entrainment at
used to study the feasibility of using ice booms to retain
the boom and the leading edge of the ice accumulation,
the ice in the lower Missouri River to reduce the
erosion of ice on the underside of the ice accumulation,
jamming potential in the Mississippi River at the
and the limiting ice boom load for ice retention were
MissouriMississippi confluence and the middle
considered. The model was verified with analytical
Mississippi River.
solutions for idealized ice jams in rectangular channels,
Numerical simulations were made with a boom
and calibrated to an ice jam that progressed up into the
located at RM 16 or RM 8.2, the two most favorable
lower Missouri River from the middle Mississippi River
locations for an ice boom. Table 3 summarizes the
during January 1977. The calibrated model was then
simulation results. In the first group of simulations,
Table 3. Summary of simulation results.
Water
Ice
Model
Water level at
Boom
Simulation
discharge
discharge
domain
downstream
location
(m3/s)
(m3/s)
cases
(RM)
boundary
(RM)
Comments
1. Simulation for
650
7.36
1320
127.10
16
High downstream water surface
Jan. 1977 jam
elevation attributable to the
event
presence of downstream ice jam.
Boom is effective. ti = 0.61.2 m,
650
6.79
513
124.36
8.2
similar to ICETHK result.
2. 100% effective
566
11.32
1320
123.63
16
With normal open water
booms
conditions, downstream water
levels are much lower than in the
two cases above.
566
11.32
513
120.94
8.2
Ice partially grounded near the
boom. Boom loads as high as 40
to 50 kN/m.
3. Boom oriented
566
11.32
1320
123.63
16
The boom may stop ice floes, but
at 45 to the flow
erosion and entrainment limit
upstream progression.
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