Bed Elevation (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
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 level at
1. Simulation for
High downstream water surface
Jan. 1977 jam
elevation attributable to the
presence of downstream ice jam.
Boom is effective. ti = 0.61.2 m,
similar to ICETHK result.
2. 100% effective
With normal open water
conditions, downstream water
levels are much lower than in the
two cases above.
Ice partially grounded near the
boom. Boom loads as high as 40
to 50 kN/m.
3. Boom oriented
The boom may stop ice floes, but
at 45 to the flow
erosion and entrainment limit