SECTION CHAIN LINK FENCE AND GATES

Transcription

1 SECTION CHAIN LINK FENCE AND GATES PART 1 GENERAL 1.01 SECTION INCLUDES A. Fabrication, furnishing and installation of chain link fence, chain link gates, and extension brackets with barbed wire RELATED SECTIONS A. Section Submittal Procedures. B. Section Structural Excavation and Backfill. C. Section Cast in Place Concrete REFERENCES A. ASTM A 121 Zinc coated (galvanized) steel barbed wire. B. ASTM F 654 Residential Chain Link Fence Gates. C. ASTM F 668 Poly Vinyl Chloride (PVC) Coated Steel Chain Link Fence Fabric. D. ASTM F 900 Industrial and Commercial Swing Gates. E. ASTM F 1083 Pipe, Steel, Hot Dipped, Zinc Coated (Galvanized), Welded, for Fence Structures. F. ASTM F 1184 Industrial and Commercial Horizontal Slide Gates SUBMITTALS A. Comply with Section B. Submit for the Engineer s information and acceptance the following: 1. The Manufacturer s Certificates verifying the materials comply with the specified standards. 2. Shop Drawings for fabrication, assembly and erection.

2 PART 2 PRODUCTS 2.01 MATERIALS Materials shall conform to the following: A. General: 1. Materials for fencing and gates shall be in accordance with the standards listed in clause All items of each type, such as posts, fabric, and accessories shall be from the same manufacturer and of the same size, design, and materials except as otherwise shown on the Drawings. 2. The fencing items and fittings shall be galvanized and where required shall have a bonded polyvinyl chloride (PVC) coating. The bond between the vinyl coating and the metal surface shall be not less than the cohesive strength of the vinyl. The color of the vinyl coating shall be as shown on the drawings or as approved by the Engineer. Extruded PVC coatings or jacketed type coatings will not be accepted. 3. Concrete for post foundations shall be as shown on drawing in accordance with Section B. Wire and Fabric: C. Posts: 1. The Chain Link Fence fabric shall be Plastic Coated with 50 mm diamond mesh of 4.0 mm diameter wire with twisted and barbed top and bottom salvages. The fabric shall be of the size and dimensions shown on the Drawings. 2. The Line Wires (3 strands) shall be Plastic Coated 4.0 mm diameter. Tying wire for fastening fabric to line posts shall be of nominal core diameter of 1.4 mm and nominal outside diameter of 2 mm. Galvanized steel bands shall be used for fastening the fabric to all corner, straining, end posts and gate frames. Intermediate, end corner, straining posts and struts shall be galvanized steel hollow circular sections to ASTM F 1083 Schedule 40. As specified on the Drawings. 1. Intermediate or Line Posts mm outside diameter and 3.91 mm wall thickness minimum. 2. End, Corner or Straining Posts mm outside diameter and 5.16 mm wall thickness minimum. 3. Struts mm outside diameter and 3.68 mm wall thickness minimum. Where specified on the drawings posts shall be fitted with snap off failing footings as detailed to permit failure of the fencing when the moment at the post base is equal to 1.2 KNm.

3 D. Gate Hinge Posts: Gate hinge posts of galvanized steel hollow circular sections to ASTM F 1083 schedule 40, with the following diameters for the nominal width of a single gate, or one leaf of a double gate: To 2.0 m width - outside diameter mm by 6.02 mm, wall thickness 2.0 m to 4.0 m width - outside diameter mm by 6.5 mm, wall thickness 4.0 m to 6.0 m width - outside diameter mm by 7.11 mm, wall thickness 6.0 m to 8.0 m width - outside diameter mm by 8.18 mm, wall thickness. E. Miscellaneous Fencing Items: F. Gates: 1. Post tops, and other fittings and hardware shall be of galvanized steel, malleable iron, or wrought iron. 2. Stretcher bars of galvanized steel, not less than 5mm by 20mm or equivalent crosssectional area, and of lengths equal to the full height of the fabric to be used. 3. Bolts, nuts and other hardware shall be galvanized. 4. Horizontal braces shall be galvanized steel pipe at least mm outside diameter and 3.2 mm wall thickness and diagonal bracing of galvanized steel truss rods at least 10 mm diameter with turnbuckles. 1. Swing gate frames: Galvanized steel hollow circular sections with oustide diameter not less than mm by 3.68 mm wall thickness welded to form a rigid frame, with cross-bracing of galvanized steel rods, 10 mm in diameter. 2. Latches for swing gates with padlock eyes, forked or plunger-bar type, operated from each side of the gate. Provide gate stops and keepers as required. 3. Hinges: manufacturer s standard type which will ensure that gates cannot be readily detached by unauthorized persons. 4. Tie wire and stretcher bars as specified for other fencing herein. G. Extension Brackets: Galvanised steel Y-shaped extension arms combined with the post cap with three slots for supporting three strands of barbed wire and of sufficient strength to withstand the loads of all the strands of barbed wire. H. Barbed Wire: Barbed wire consist of minimum three strands of 2.5 mm wire, otherwise twisted with two-point 2.1 mm or heavier aluminum barbs spaced not more than 75 mm apart.

4 PART 3 EXECUTION 3.01 ERECTION A. Posts: 1. Erect space line posts not more than 3m apart, measured parallel to the slope of the natural ground. Set vertically the posts except in unusual situations as determined by the Engineer where posts are to be placed perpendicular to the slope of the ground. 2. Install gate posts where shown on the Drawings. Install corner posts where the o change in direction is 15 or more. Place straining posts not more than 150 m apart o in a straight run and where the line changes direction by 15 or more. B. Excavation for Posts: 1. Excavate in firm, undisturbed, or compacted soils to the minimum diameters and depths shown. Drill holes augered, or excavated with a post-hole digger. 2. In rock, submit for the Engineer s approval, proposals for grouting line or straining posts into 150 mm diameter holes at least 300 mm deep for line posts and not less than 450 mm deep for all other posts. C. Setting Posts: 1. Place posts vertically and aligned within a tolerance ratio of 1 in 500. Set the top of posts to the required height, and do not cut off. 2. Where snap off fence posts are required, place them in post holes with the snap fitting oriented to permit failure in the direction of the stream channel. Do not extend the snap off fitting more than 150 mm above the channel invert, but must be clear of the concrete base. 3. Place concrete of class C20S, in post holes in a continuous placement and compact by rodding or by use of mechanical vibrators. Trowel-finish the top of footings and slope it to drain away water. 4. Install temporary guys or braces as required to hold the posts in position until the concrete has set sufficiently, and do not hang any material on the posts for the first seven days after placing the concrete. 5. If the ground is firm enough to permit excavation of a post hole to neat lines, the concrete may be placed without forms by completely filling the hole. Under these conditions moisten the earth coming in contact with the concrete prior to placing the concrete. 6. When the ground cannot be satisfactorily excavated to neat lines, use forms for footings. Remove the form after 24 hours of placing concrete and paint the surface with 2 coats bituminous dampproofing. Backfill the footing with moistened material and tamp thoroughly. Cover the top of the concrete with not less than 100 mm of loose moistened material.

5 7. Cure the concrete for a minimum of seven days before stretching the fabric and installing brace assemblies or gates. D. Struts and Braces: Provide these at each gate, corner, straining and end posts at midheight of the fabric. Extend the brace horizontally between the gate, corner, straining or end post and the adjacent line post. Provide the diagonal rod with a turnbuckle not less than 10 mm in diameter, and extend it from the line post end of the horizontal brace to the base of the gate, corner, straining or end post. Where fence lengths is of 90 m or longer, end at gate, corner, straining or end posts, provide a second similar diagonal rod from the midpoint of the gate, corner, straining or end post to the top of the adjacent line post. E. Tension Wires: Fasten tension wires by clips at each gate, corner, straining or end post, and stretch it tight with turnbuckles or propose an alternative method for approval of the Engineer. Taut the bottom tension wire between posts, 50 mm or less above the ground surface except where special closures are required. F. Fabric and Barbed Wire: G. Gates: 1. Place the fabric on the outside of the posts, evenly stretched, and fastened to the post by bands or tie wires not more than 360 mm apart on the posts. Fasten the fabric to the line wires by tie wires spaced not more than 600 mm apart. 2. Attach the stretcher bars to the fabric by clamps or other approved mechanical means. Provide one stretcher bar for each gate, straining and end post, and two for each corner post. Provide sufficient clips for attaching the fabric and stretcher bars to the post at intervals not more than 400 mm apart. 3. Install three strands of barbed wire in to the slots of each arm of the extension brackets and fastened by steel wire keys. Provide continuous barbed wire for each run of fence, drawn out and fastened securely with wire stretching bands to the extension brackets of the gate corner, straining or end posts. 1. Erect the gates plumb and true, complete with all the necessary accessories for satisfactory operation. Attach the chain link fabric to the gate frames by stretcher bars and tie wires as for the fence construction, and space tension connectors approximately 300 mm apart. Hung each gate on at least two hinges, clamped securely to the gatepost and allowing the gate to swing back against the fence. 2. Design the hinges and arrange such that the gate cannot be removed without mechanically dismantling the hinges. 3. Provide extension arms on the end posts to carry strands of barbed wire aligned horizontally with those on the adjacent fence. END OF SECTION 02832