EM 1110-2-1100 (Part V)
31 Jul 2003
EXAMPLE PROBLEM V-4-6
FIND:
Volume per unit length of shoreline required to widen the dry beach by 30 m. Disregard any
volume necessary to makeup for a preproject sediment deficit in the beach profile.
GIVEN:
Berm height of 2.5 m and depth of closure of 6 m. Native sand median grain size of 0.27 mm
and fill sand median grain size of 0.36 mm.
SOLUTION:
Values of the A parameter for native and fill sand are read from Table III-3-3.
AN = 0.119 m1/3, AF = 0.137 m1/3
Determine whether profile is intersecting or nonintersecting.
Equation V-4-7 gives
3/2
3/2
0.119
0.119
30@
' 0.893 < 1
%
6
0.137
therefore, the profile is intersecting and Equation V-4-10 is applicable.
Equation V-4-10 gives
3
@ 30 5/3 @ 0.119 @ 0.137
5
' 137 m 3/m
V '30 @ 2.5 %
2/3
0.137 3/2 & 0.119 3/2
By comparing with Example V-4-3, it is seen that using the coarser fill material specified in this example
requires approximately 45 percent less volume than that required using compatible material, to generate
the same equilibrium beach width.
required interval/quantity will vary depending on the climatic conditions that occur. Ideally, the need for
renourishment will be determined by monitoring performance of the fill. Some level of renourishment, or
maintenance such as redistribution of sand within the project domain, is needed when the project design cross
section is no longer in place. In this situation, the desired level of protection is compromised. However, the
schedule for periodic renourishment may be more fixed, in the sense that budgeting for it may have been set
at the outset of the project. If renourishment is needed before the scheduled time, it can be handled as an
emergency maintenance action (see Part V-4-1-m). Should permanent changes to the periodic renourishment
cycle (volume and/or frequency) be necessary, a reformulation of the project may be needed. Having an
adequate project monitoring plan in place is very important. Monitoring data are particularly valuable if the
project does not perform as designed. The data can be analyzed to evaluate the nature of the conditions that
prompted the need for unexpected renourishment and assess their frequency of occurrence. Analysis of the
V-4-48
Beach Fill Design
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