continuous between terminal posts; however, runs between terminal posts
shall not exceed 152.4 m (500 feet) 500 feet. Any damage to galvanized
surfaces, including welding, shall be repaired with paint containing zinc
dust in accordance with ASTM A 780.
3.2
EXCAVATION
Post holes shall be cleared of loose material. Waste material shall be
spread where directed. The ground surface irregularities along the fence
line shall be eliminated to the extent necessary to maintain a [25] [50] mm
[1] [2] inch clearance between the bottom of the fabric and finish grade.
3.3
POST INSTALLATION
3.3.1
Posts for Chain Link Fence
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NOTE: For fences over 1.83 m (6 feet) tall in areas
of frequent high winds (113 kph (70 mph) or
greater), hole diameters of 406 mm (16 inches) for
terminal posts and 305 mm (12 inches) for line posts
will be specified.
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Posts shall be set plumb and in alignment. Except where solid rock is
encountered, posts shall be set in concrete to the depth indicated on the
drawings. Where solid rock is encountered with no overburden, posts shall
be set to a minimum depth of 457 mm (18 inches) 18 inches in rock. Where
solid rock is covered with an overburden of soil or loose rock, posts shall
be set to the minimum depth indicated on the drawing unless a penetration
of 457 mm (18 inches) 18 inches in solid rock is achieved before reaching
the indicated depth, in which case depth of penetration shall terminate.
All portions of posts set in rock shall be grouted. Portions of posts not
set in rock shall be set in concrete from the rock to ground level. Posts
set in concrete shall be set in holes not less than the diameter shown on
the drawings. Diameters of holes in solid rock shall be at least 25 mm (1
inch) 1 inch greater than the largest cross section of the post. Concrete
and grout shall be thoroughly consolidated around each post, shall be free
of voids and finished to form a dome. Concrete and grout shall be allowed
to cure for 72 hours prior to attachment of any item to the posts. Group
II line posts may be mechanically driven, for temporary fence construction
only, if rock is not encountered. Driven posts shall be set to a minimum
depth of 914 mm (3 feet) 3 feet and shall be protected with drive caps when
being set. For high security fences, fence post rigidity shall be tested
by applying a 222.4 newtons (50 pound) 50 pound force on the post,
perpendicular to the fabric, at 1.52 m (5 feet) 5 feet above ground; post
movement measured at the point where the force is applied shall be less
than or equal to 19 mm (3/4 inch) 3/4 inch from the relaxed position; every
tenth post shall be tested for rigidity; when a post fails this test,
further tests on the next four posts on either side of the failed post
shall be made; all failed posts shall be removed, replaced, and retested at
the Contractor's expense.
3.3.2
Posts for Farm Style Fence
For wood posts, the Contractor shall excavate to depth indicated and brace
post until backfill is completed. Backfill shall be placed in layers of
229 mm 9 inches or less, moistened to optimum condition, and compacted with
hand tampers or other approved method. Posts shall be set plumb and in
SECTION 02821A
Page 13
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