SCOPE OF WORK
The work
specified in this section covers the furnishing of all materials, labor,
transportation, equipment and services necessary for the installation of
fences, gates, space, guard rails and handrailing as shown on the approved
drawings or as directed by the Owner.
The work
performed shall be in accordance with the specifications. The materials and
workmanship for fence and gates shall conform to the following or approved
equal standards :
- United States Department
of Commerce (USDC): USDC ‑
"CS246‑Steel Galvanized Fence Fabric".
- "Industrial Steel
Specifications for Fence Posts, Gates and Accessories".
FENCE TYPE
Fencing
shall consist of hot dip galvanized steel coated with polyvinyl chloride coloured
blue with a fabric height and width of 180 cm and an overall height of 210 cm
from the bottom of the fabric to the top of barbed wire. The fence shall have a
top rail, bottom tension wire and three strands of barbed wire mounted on 45
degree extension arms. The upper strand shall be approximately 30 cm out from
the fence and 30 cm above the top of the panel. Posts shall be set in concrete.
MATERIALS
FENCE
FABRIC
Fence fabric shall be
vinyl-coated galvanized fabric, 3.51 mm diameter steel wire in both the
horizontal and vertical directions. Galvanizing shall be a minimum thickness of
80 microns.
Fabric
steel wires shall have a minimum tensile strength of 4,100 kg/cm2.
POSTS,
RAILS, BRACES, GATES AND APPURTENANCES
General
Pipe hot
dip galvanized pipe conforming to ASTM A120‑79.
Fittings
and Accessories: Bolt & nut, U clip and post. All shall be hot dip
galvanized.
Galvanizing: Hot dip
galvanized pipe (inside and outside) and frame steel profile sections (all
surfaces) and other ferrous parts, with a weight of zinc coating not less than 80
microns of thickness.
Sizes of
Material for Posts, Rails, Braces and Gate Frames shall conform to the
following dimensions or as shown on the approved drawings:
End
Corner and Pull Posts: round 62 mm nominal diameter, 73 mm OD.
Intermediate
Posts: round 50 mm nominal diameter, 60 mm OD.
Gate
Posts: round 89 mm nominal diameter, 101 mm OD. for 2 to 4 meter nominal width
of gate, single or double swing, or sliding gates.
Exterior
Frames for Gates: Hot dip galvanized, round 38 mm nominal diameter, 48.26 mm
OD.100 mm x 50 mm and 3.5 mm of thickness.
Interior
bracing for gates : round 32 mm nominal diameter, 42 mm OD.
ATTACHMENTS
To End,
Corner, Intermediate and Gate Posts: Shall be as recommended by the fence
manufacturer or as approved by the Owner.
To
Intermediate Posts: Fasten fabric with No. 6 gauge galvanized steel wire clips
spaced not more than 375 mm center to center.
To Top
Rail : Fasten fabric with 9 gauge galvanized steel wire clips spaced not more
than 600 mm center to center.
BARBED
WIRE AND ATTACHMENTS
Three
lines of two strand 2.5 mm diameter steel wire with 2.11 mm diameter four point
barbs spaced approximately 125 mm on center.
All wire
shall be hot dip galvanized, with the weight of zinc coating per square meter
of surface area not less than 0.24 k g/m2 for 2.5 mm diameter wire
and not less than 0.20 k g/m2 for 2.11 mm diameter wire.
Barbed
wire shall be fastened to extension arms with heavy galvanized steel pins, and
to post extensions with galvanized steel bands.
Contractor shall provide barbed wire
across the tops of gates, as well as continuously along the entire top of the
fence.
FENCING
DETAILS
Post Setting: Contractor shall provide
posts of sufficient length for depths indicated on the approved drawings.
Post Tops and Extension Arms: Malleable
iron or pressed steel, with post tops for square posts designated to exclude
moisture from inside the posts, and with integral extension arms for barbed
wire, as follows:
For
Intermediate Posts: Extension arm or arms extending at 450 angles and slotted
to carry three evenly spaced strands of barbed wire with the top strand or
strands located approximately 35 cm above the top of the fence panel.
For End
and Corner Posts: Same construction as for intermediate posts, with the post
top and extension securely riveted to posts, or extend posts up to the full
height required and provide a post top.
Gate
Post: Extend posts up to the full height required and provide post top.
Top Rail
Details: Provide with 17.5 cm long outside sleeve type couplings every 6 m on
center. The top rail shall pass through the base of the intermediate post tops
and form a continuous brace from end to end of each stretch of fence. Securely
fasten the top rail to terminal posts with heavy pressed steel connections.
Brace Details: Provide
at both sides of corner posts, and between terminal posts or gate posts and
first adjacent intermed.ate posts. The compression brace shall be pipe, same as
the top rail, installed midway between the top rail and ground and extending
from the braced post back to the intermediate post. Securely fasten the
compression brace to posts with heavy pressed steel connections. Securely
fasten the truss from the intermediate post back. to the braced post with a 10
mm diameter truss rod complete with tightening nut or turnbuckle.
GATES
Gate
shall be swing and sliding type. The swing type shall be hinged to swing 180
degrees from closed to open and sliding type shall be rolled on rail, complete
with frames, latches, stops, keepers, hinges, fabric and braces rail. Gate
leaves shall have intermediate members and diagonal truss rods as required for
rigid construction and shall be free from sag or twist. Joints between frame
members shall be made by welding or by means of heavy fittings, and shall be
rigid and watertight. Gate fabric shall be the same as fence fabric and shall
be attached to the frame ends by stretcher bars, bolt hooks or other mechanical
means.
Hinges
shall be of a heavy pattern with large bearing surfaces and shall not twist or
turn under the action of the gate. Latches shall be the plunger bar type, full
gate height, and arranged to the gate stop, except that single gates less than
3 m wide may be provided with a forked latch. Latches shall be arranged for
padlocking with a padlock accessible from both sides of the gate. Stops shall
consist of a roadway plate with an anchor set in concrete and arranged to
engage the plunger.
Keepers
shall consist of mechanical devices for securing and supporting the free end of
the gates when in the full open position. Keepers shall be mounted on 70 mm
outside diameter pipe posts filled with concrete and set in concrete
foundations.
Gates
shall be installed so that they cannot be removed without disassembly of the
hardware. Hardware attachment bolts shall be pinned so that removal will be
difficult.
FENCE
CONSTRUCTION
The
installed fence shall conform to the alignment and finish grade indicated on
the approved drawings. Unless otherwise indicated or specified, all posts shall
be plumb and spaced 2.40 m apart. Where necessary, the fence grade shall be
adjusted to fit the ground contour by slipping the fence fabric links. On steep
grades, the posts may be set normal to the slope, provided transition sections
are constructed. Ground surface irregularities shall be machine graded as
required to eliminate frequent changes in vertical alignment and to provide a
smooth profile for the fence. Clearance below the bottom of the fence shall not
exceed 100 mm.
It is
the intent of these specifications that the plan and profile of each reach of
fence between corner posts, or between corner posts and gate posts, shall be
straight. The Contractor shall grade ground surfaces as required to achieve the
straight profiles before each reach of fence is installed.
Where posts are set in
earth, concrete foundations 90 cm deep shall be provided. Concrete foundations
shall be not less than 30 x 30 cm for line posts and with a diameter not less
than the post size plus 20 cm for terminal and gate posts. Foundations shall
extend above the ground surface and shall be crowned approximately 50 mm.
Concrete for foundations shall conform to the cast in place concrete section.
Each foundation shall be cured for at least 72 hours before further work is done
on the post.
GUARD RAIL
MATERIALS
The rail
elements shall be corrugated sheet steel beams conforming to plan details and
the thickness of the metal shall be as specified on the plans. All guard rail
elements, terminal sections and fittings shall be interchangeable with similar
parts, regardless of source or manufacturer. The guard rail, terminal section
and appurtenance shall be in accordance with AASHTO Designation: M 185, the
plans and the following requirements:
- Unless otherwise
specified, the beam shall be Class B, with buffer end sections being either
Class A or B.
- The beams shall be
galvanized after fabrication with Type 1 or 2 coating in accordance With AASHTO
Designation: M‑180. The fabrication shall file a Brand Registration and
Guarantee in accordance with AASHTO designation M‑180. Certificates of analysis
shall be furnished for each per shipment covering all tests and measurements
required by AASHTO Designation: M‑180.
Guard
Rail Posts and Spacer Blocks
Railing
posts shall be of treated timber. Spacer blocks shall be of the same material
and with the same treatment as the post. Timber posts shall be treated timber
of Damar Laut and shall be of the section and length as specified or as shown
on the approved drawings.
The
timber is treated by Creosote, Creosote Coal‑Tar Solution or Pentachlorophenol
Petroleum Solution. Treatment shall he 251 kg per cubic meter of timber and the
type preservatives to be used are as follows:
- Creosote Oil ‑ AWPA P1
for regular treatment; AWPA P13 for marine treatment.
- Creosote Coal ‑ Tar
Solution ‑ AWPA P2, Grade A, for regular treatment; AWPA P12 for marine
treatment. The ratio shall be 80% Creosote Oil and 20% coal‑tar.
- Pentachlorophenol ‑
Petroleum Solution ‑ AWPA P8 and P9.
CONSTRUCTION
The installed
guard rail shall conform to the alignment and finish grade as indicated on the
approved drawings. Unless otherwise indicated or specified, all guard rail
posts shall be plumb and spaced 4 meters apart. Where posts are set in earth,
concrete foundations shall be provided. Concrete for foundations shall conform
to the requirements specified in Specification refers to "Concrete
Works". Concrete shall be GRADE 22.
The
length, depth and other sizes of the guard rail, guard rail post and spacer
blocks shall be as indicated on the approved drawing or as directed by the
Owner.