MIL-HDBK-1025/5
Provide sliding ends for gangways weighing less than
j)
500 pounds. For heavier gangways, provide rollers and aprons. The apron
plates shall be long enough to clear the ends of the roller guides at low
water level and attached to the bottom end of the gangway with a pipe-and-rod
hinge.
(See Figure 18.)
Design Criteria for Other Sheltered Basin Structures
2.4
Perimeter Stabilization
2.4.1
Objectives.
Perimeter stabilization shall be provided:
2.4.1.1
To retain the perimeter material or to hold it on a given
a)
slope against such internal forces as those causing sloughing or piping of
material under a wall or through a revetment.
To prevent damage to the perimeter by external forces which
b)
might erode or damage the slope or perimeter wall through wave action,
currents, and impact by floating objects.
Structures. The perimeter inside the sheltered harbor basin shall,
2.4.1.2
depending on the bank conditions and the degree of stabilization required, be
designed as:
Perimeter beach of existing or imported materials.
a)
Revetted slope.
b)
Gabioned slope.
c)
Vertical bulkhead.
d)
Some combination of the above.
e)
Perimeter Beach
2.4.2
Slopes
2.4.2.1
Where economic considerations warrant the perimeter of the
a)
basin be a sand beach, the slope shall not, ordinarily, be steeper than 1 on 8
(1 on 10 for fine sand) within the maximum range of water-level fluctuation in
the basin.
Where the shore face consists of gravel, pebbles, or similar
b)
rock fragments or sizes rather than sand, littoral transport processes are
usually too weak to cause any significant lateral displacement and the slope
may be increased up to about 1 on 5.
Underwater stable slopes at depths of 3 ft (.91 m) or more
c)
below extreme low water vary from about 1 on 4 for cohesionless fine silty
sands to about 1 on l-1/4 for some clayey soils in cuts.
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