at totally laterally restrained points, with structural slide bearings.
Construct slide bearings with slide bars or other methods to prevent
possible accumulation of ash, dirt, and other materials on the bearing
area. Slide bearings shall have fluoroplastic self-lubricating bearing
elements.
2.13.3
Miscellaneous Steel
Handrail shall be 40 mm 1 1/2 inch round black standard weight pipe
conforming to ASTM A 53 Type E or S, Grade B, with two horizontal pipe runs
at 584 mm and 1067 mm1 foot 11 inches and 3 feet 6 inches above top of
walking grating. Handrail, accessories, and kickplates shall be hot-dipped
galvanized after fabrication in accordance with ASTM A 123/A 123M.
Kickplates shall be 6 mm 1/4 inch thick steel plate. Steel floor grating
shall be one-piece, resistance-welded steel construction without notching
of bearing or crossbars before welding. Main bars shall be 5 mm 3/16 inch
thick, spaced not more than 30 mm 1 3/16 inches on centers. Serrate main
bars for outdoor use. Crossbars shall be spaced at four inches on centers
and shall be one of the following shapes: hexagon with 8 mm 5/16 inch
diameter of inscribed circle; rectangular 13 by 5 mm 1/2 by 3/16 inch;
square 6 mm 1/4 inch with spiral twist; round 8.33 mm 21/64 inch diameter.
Grating materials shall be of welding quality and conform to the following
standards: (1) Crossbar - ASTM A 108 - Grade 1010. (2) Main Bars - ASTM A
108 - Grade 1015. Grating finish shall be hot-dip galvanized after
fabrication in accordance with ASTM A 123/A 123M. Stairs shall be
open-riser type with grating treads and grating landings conforming to
"Steel Floor Grating" an with main bars 25 by 5 mm 1 by 3/16 inch(Serrate
main bars for outdoor use). Stair treads and landings shall be hot-dip
galvanized after fabrication in accordance with ASTM A 123/A 123M. Stairs
shall be supported with carrier plates 65 by 5 mm 2 1/2 by 3/16 inch by
tread width tack welded to all bearing bars and with 5 mm 3/16 inch fillet
welds (one side only) to the front two and the rear bearing bars, or
supported with 35 by 22 by 3 mm 1 3/8 by 7/8 by 1/8 inch minimum size angle
welded to the front and rear bearing bar (one side only). Provide
subframing so grating span on landings does not exceed 1067 mm 3 feet 6
inches. Provide nosing on all treads and at the head of all stairs.
Raised pattern floor plate shall be 6 mm 1/4 inch minimum thickness with
surface deformation of the four-way type. Hot-dip galvanize raised pattern
floor plate and straighten warped plate after galvanizing so that warpage
does not exceed one inch for every 3 meters 10 feet in any direction.
2.13.4
Fabrication
Shop fabrication and assembly of steel structures shall be done in
conformance with AISC Specifications, Codes, and Standards. Field welding
shall be shielded metal arc or submerged arc. Shop welding shall be
shielded-metal arc, submerged arc, flux-core arc, or gas metal arc. Welding
shall be done in conformance with the requirements of the AWS D1.1/D1.1M
and AISC Specifications. Field welds shall be shown on erection drawings
in conformance to the applicable standards. Shop connections shall be
welded, riveted, or bolted with high-strength bolts at the Contractor's
option and as allowed by the seismic code. Unless restricted by
consideration of clearance or seismic design criteria, field connections
shall be shown as bolted friction type using ASTM A 325M ASTM A 325 or ASTM
A 490M ASTM A 490 bolts and shall be designed to conform to AISC
specification for "Structural Joints Using ASTM A 325M ASTM A 325 or ASTM A
490M ASTM A 490Bolts." Form and weld handrails and do not exceed 1.83
meters 6 feet from center-to-center of posts. Grind welds smooth and even
with the surface of the pipe, remove weld splatter. Carefully form
SECTION 15864N
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