EP 1110-345-102
31 Aug 95
CHAPTER III
MISCELLANEOUS CONSIDERATIONS
3-1. Earth Cover. Material for earth cover over magazines
should be reasonably cohesive (solid or wet clay, or similar
types of soil may not be used as they are too cohesive), free
from deleterious organic matter, trash, debris, and stones
heavier than 10 pounds or larger than 6 inches in diameter. The
larger stones should be limited to the lower center of fills and
will not be used for earth cover over magazines. Compaction and
surface preparation should be provided, as necessary, to maintain
structural integrity and avoid erosion. When it is impossible to
use a cohesive material, for example, in sandy soil, the earth
cover over magazines should be finished with a suitable material
to ensure structural integrity. The minimum earth cover over the
top of the magazine should be 2 feet, with a slope of 2
horizontal and 1 vertical. periodic maintenance must be
performed to ensure restoration of erosion of cover below the 2-
foot depth requirement. The earth-cover over and around the
magazine is a critical element of the standard design. It
provides some confinement and tends to directionalize the
explosive force both upward and outward from the door end of the
donor magazine. The cover over receiver magazines resists
fragment penetrations and provides mass to the arch to resist the
blast pressure. Where practical, earth cover should be seeded to
prevent soil erosion. Where rainfall is insufficient to maintain
grass cover, soil stabilization methods should be used.
3-2. Waterproofing. provisions are made in the standard
magazine designs to ensure watertightness of the magazine. The
type of magazine (steel or concrete) generally dictates the type
of waterproofing used. An elastomeric membrane is most suitable
on concrete arches, and a bituminous waterproofing is suitable on
steel magazines. Moisture proofing difficulty is increased with
steel-arch magazines because of the many lineal feet of joints.
3-3. Drainage Systems. Drainage systems are provided around the
magazines to channel the water away from the structure. For
concrete magazines, the drainage composite system is recommended.
The older sand-gravel filter system is more costly and should be
avoided, except for the steel arch where it is recommended due to
the corrugated configuration.
3-4. Doors. Magazine doors are either of the swinging or the
sliding type. Sliding doors are generally specified on large
magazines, and swinging doors on smaller magazines. Doors are
A-21
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