05510: TAPERED STEEL TROLLEY POLES AND ACCESSORIES

Size: px
Start display at page:

Download "05510: TAPERED STEEL TROLLEY POLES AND ACCESSORIES"

Transcription

1 PART 1 GENERAL 1.01 DESCRIPTION A. The Vendor shall fabricate, furnish, test and deliver tapered steel trolley poles, including base plates, reinforced hand holes, anchor bolts, nuts and washers, and accessories as specified in this section and as shown on the attached drawings, reference Attachments H, I, J, and K and Caltrans 2010 Standard Plan ES-7C, web location: The tapered steel trolley poles may simultaneously support Overhead Contact System (OCS), streetlights, traffic signals, electrical feeders, riser conduits, and other items as applicable REFERENCES A. General Requirements: Comply with the applicable Reference Standards, and with other requirements indicated in this Section. B. All materials and workmanship shall conform to the latest published applicable provisions of the following standards: 1. American Society for Testing and Materials (ASTM) ASTM A 36/ A 36M ASTM A 123/ A 123M ASTM A 153/ A 153M ASTM A 194/ A 194M Standard Specification for Carbon Structural Steel Standard Specification for Zinc (Hot- Dip Galvanized) Coatings on Iron and Steel Products Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High- Pressure and High-Temperature Service

2 ASTM A 325 ASTM A 354 ASTM A 385 ASTM A 563 ASTM A 572/ A 572M ASTM A 595/ A 595M ASTM A 780/ A 780M ASTM A 1008/ A 1008M ASTM E 8/ E 8M ASTM F 436 Standard Specification for Structural Bolts, Steel, Heat Treated, 120/ 105 ksi Minimum Tensile Strength Standard Specification for Quenched and Tempered Alloy Steel Bolts, Studs, and Other Externally Threaded Fasteners Standard Practice for Providing High- Quality Zinc Coatings (Hot-Dip) Standard Specification for Carbon and Alloy Steel Nuts Standard Specification for High- Strength Low-Alloy Columbium- Vanadium Structural Steel Standard Specification for Steel Tubes, Low Carbon, Tapered for Structural Use Standard Practice for Repair of Damaged and Uncoated Areas of Hot- Dip Galvanized Coatings Standard Specification for Steel, Sheet, Cold-Rolled, Carbon, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, Solution Hardened, and Bake Hardenable Standard Test Method for Tension Testing of Metallic Materials Standard Specification for Hardened Steel Washers

3 2. American Welding Society (AWS) ANSI/ AWS D1.1 Structural Welding Code Steel 3. Caltrans 2010 Standard Plan ES-7C Electrical Systems (Signal and Lighting Standard, Case 1 Signal Mast Arm Loading, Wind Velocity = 100 mph and Signal Mast Arm Lengths 15 to 30 ) SUBMITTALS The Awarded Vendor shall submit the following items for approval prior to ordering and fabrication: A. Shop drawings for steel poles with base plate, pole cap, reinforced handhole openings and covers, street light connections, and other applicable accessories. B. Shop drawings for anchor bolts with nuts and washers. C. Certified test reports for welding and galvanizing. D. Certified test results from an independent recognized testing agency or mill laboratory or mill to certify that the materials are in accordance with the Contract Documents. E. Test data and results of pole deflection test. PART 2 PRODUCTS 2.01 STEEL POLES AND ACCESSORIES A. Pole Assemblies: 1. Tapered tubular steel trolley poles to be provided by the Vendor shall be of single or double thickness, hot rolled, basic open-hearth plate or sheet steel conforming to ASTM A 572/ A 572M, Grade 55, Standard Specification for High-Strength Low-Alloy Columbium- Vanadium Structural Steel, ASTM A 1008/ A 1008M, Grade 55, Standard Specification for Steel, Sheet, Cold-Rolled, Carbon, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, Solution Hardened, and Bake

4 Hardenable, or ASTM A 595/ A 595M, Grade A, Standard Specification for Steel Tubes, Low Carbon or High-Strength Low- Alloy, Tapered for Structural Use. All fabricated new poles shall have minimum yield strength of 55,000 psi after cold working. The manufacturer shall furnish an affidavit certifying that the material in the finished trolley poles meets the guaranteed minimum yield strength of 55,000 psi. 2. Poles shall taper uniformly, starting with the base or butt end, decreasing in diameter at the rate of not more than 0.14 inch per foot of length. The actual ground line diameter of a pole shall not be more than 1/8 inch over or under the specified nominal pole diameter. The difference between the diameters taken at right angles to each other at any cross section perpendicular to the axis of the pole shall not exceed one percent (1%) of the nominal diameter at that point. Wall thickness shall not be less than ninety percent (90%) of the specified thickness. 3. Poles with variations in nominal diameter and/ or wall thickness in excess of those specified in item 2 above shall be submitted, for approval, with calculations showing the actual capacity of the pole, and the capability of its accompanying base plate, anchor bolts, and anchor plate to develop the pole strength. Proposed pole must satisfy deflection criteria and limits specified in Table I. Calculations must be prepared, stamped, and signed by a Professional Structural or Civil Engineer registered in the State of California. Variation in the nominal diameter of pole shall not exceed four percent (4%) for poles under 12 inches diameter, and eight percent (8%) for poles 12 inches and larger in diameter as shown in Attachment J, Standard Drawing CL-7971, Rev A reinforced handhole opening, 4 inches by 6 inches, shall be provided on each pole. The handhole shall be reinforced to provide shaft strength equal to or exceeding that of similar pole with no handhole opening. The handhole will be located at ninety degrees (90 ) clockwise from streetlighting arm fittings and shall be provided with rain-tight covers and attachment hardware. 5. Each pole shall have a ground sleeve of matching grade, 2 feet 6 inches long, 3/8 inch thick. Each pole shall have a base plate in accordance with the type of pole required and conforming to ASTM A 36/ A 36M, Standard Specification for Carbon Structural Steel. The pole, ground sleeve, and base plate shall be welded together as

5 one whole unit as shown on Attachment J, Standard Drawing CL- 7971, Rev Each pole shall be equipped with a 3 inches iron J-hook and a ground lug, with hexagon nut, flat washer, and spring washer, welded to the inside of the pole as shown in Attachment I, Standard Drawing B-1646, Rev NOT USED 8. Provide 2 inches high characters made up of welds welded onto the pole, approximately 5 feet above the ground line, identifying the type of pole, for example, #761N. The lettering shall be vertical and protrude at least 1/8 inch, but not more than 3/16 inch. 9. All items described above shall be hot-dip galvanized inside and outside after fabrication per ASTM A 123/ A 123M, Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products, and A 385, Standard Practice for Providing High- Quality Zinc Coatings (Hot-Dip), as applicable. Zinc coating shall weight at least 2.0 ounces per square foot. 10. Four (4) anchor bolts shall be provided with each pole, unless otherwise noted. The diameter of the bolts is as specified on Attachment J, Standard Drawing CL-7971, Rev 2 and conforming to ASTM A 325, Standard Specification for Structural Bolts, Steel, Heat Treated, 120/ 105 ksi Minimum Tensile Strength, Type I, and ASTM A 354, Standard Specification for Quenched and Tempered Alloy Steel Bolts, Studs, and Other Externally Threaded Fasteners, Grade BC. The upper and lower ends of each anchor bolt shall be threaded and furnished with four (4) hexagonal nuts and four (4) washers. The top 2 feet of all anchor and all associated items (i.e., nuts, washers, and anchor bolts) shall be galvanized conforming to ASTM F 2329, Standard Specification for Zinc Coating, Hot-Dip, Requirements for application to Carbon and Alloy Steel Bolts, Screws, Washers, Nuts, and Special Threaded Fasteners. 11. All nuts shall be in accordance to ASTM A 563, Standard Specification for Carbon and Alloy Steel Nuts, Grade DH, or ASTM A 194/ A 194M, Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service, Grade 2H, or both. All washers shall conform to ASTM F 436, Standard Specification for Hardened Steel Washers

6 B. Pole Accessories: 2.02 FABRICATION 1. For poles with traffic signals and street lighting, provide necessary elbows, reinforced handhole with cover, attachment hardware, grounding stud, and 2-bolt simplex arm attachments, where required, as indicated on Attachment H, Standard Drawing B-1645, Rev For poles requiring feeder riser cable outlet, provide necessary feeder riser elbow and reinforcing collar plate to accommodate the welding necessary for the installation. The collar plate shall be 1/4 inch thick and furnished with a hole for the elbow and bent to fit flush on the pole s surface. See Attachment I, Standard Drawing B- 1646, Rev For poles with decorative streetlight, provide pole tenon for streetlight and cap attachment. Pole tenon shall be Schedule 40 steel pipe welded onto 3/8 inch steel plate, and with the steel plate welded on to the top of steel pole. The pipe and plate sizes shall be as indicated on the Drawings and painted to match the pole color. 4. For poles with Cobra head type streetlight, provide reinforced handhole with cover, attachment hardware, grounding stud, and 2- bolt simplex arm attachments, where required, as indicated on Attachment H, Standard Drawing B-1645, Rev For poles with traffic signal mast arm, provide mast arm connection where required, per Caltrans Standard Drawings, as indicated on the Drawings. A. After rough forming of the tapered tubular steel poles, the longitudinal seam shall be welded by an approved welding process, and the weld must be ground or rolled smooth. After rough forming and welding, the tube shall be longitudinally cold-rolled on a hardened steel mandrel to the finished shape. This cold working of the steel in the pole shall raise the yield strength of the steel in the finished pole to guaranteed minimum yield strength of 55,000 psi. All welds shall conform to AWS Specification D1.1, Structural Welding Code Steel

7 B. Transverse welds joining tapered sections will be allowed provided such welds are full penetration butt welds to back-up plates conforming to AWS Specification D1.1, Sections 1 through 8. Transverse welds shall be ground or rolled smooth. Back-up plates shall be closely fitted to the inner pole surface with smoothly beveled edges such that insulated wire installed within the pole will not be scraped or otherwise damaged. C. All materials shall meet ASTM E8/ E 8M, Standard Test Methods for Tension Testing of Metallic Materials SHOP INSPECTION A. At the request of the Engineer, the Vendor shall make arrangements for the Engineer to inspect the poles at the manufacturing plant prior to shipment. The Vendor shall provide all reasonable facilities and information necessary for the Engineer to ascertain that the poles are being furnished in accordance with these Specifications, and to witness the pole deflection tests when such tests are required POLE DEFLECTION TEST A. Pole deflection testing shall be required for all pole types. Tests shall be conducted on not more than five percent (5%) of the poles in any lot of twenty (20) or more and only one (1) pole in any lot under twenty (20). A lot is defined as the number of poles of any one (1) type covered by the Contract. B. Each test pole shall be rigidly anchored to a foundation or test block and subjected as a cantilever to the respective test loads (2/3)P and P given in Table I. Loads shall be applied at right angles to its longitudinal axis and the handhole in neutral position. Under the load (2/3)P, the pole at point of loading shall show a deflection not to exceed six percent (6%) over the adjusted limit y(2/3*p) given in Table I. After removing the load P, the pole at point of loading shall show a permanent set not to exceed ten percent (10%) of its temporary deflection, y(p). The permanent set needs not to be less than ½ inch. C. The general deflection formula for the elastic deflection of a tapered tubular steel pole is as follows: y = {4P/(E* *t)}[la 3 /(D 2 2 (D 2 +D 1 )) + 4*La 3 /(3(D 2 +D 1 ) 3 ) + 4*La 3 (D 2 - D 1 ) 2 /(5(D 2 +D 1 ) 5 ) + ]

8 Where: y = Deflection of pole at point of application of load P (inches) P = Transverse load applied to pole (lbs) E = Modulus of Elasticity (29,000,000 psi) = t = Wall thickness of pole (inches) La = Length of pole above ground to point of application of load P (inches) D 2 = Outside diameter of pole at ground line minus wall thickness (inches) D 1 = Outside diameter of pole at point of application of load P minus wall thickness (inches) D. Adjusted deflections for (2/3) P load shown in Table I have been increased by ten percent (10%) over values computed from above formula to take care of manufacturing tolerances. E. At the option of the Engineer, the Vendor shall acquire the services of an independent agency to witness the testing and certify the results of the test at no cost to the City. A California Professional Civil Engineer or Structural Engineer shall do the certification. TABLE I - POLE DEFLECTION LIMIT y = {4P/(E* *t)}[la 3 /(D 2 2 (D 2 +D 1 )) + 4*La 3 /(3(D 2 +D 1 ) 3 ) + 4*La 3 (D 2 -D 1 ) 2 /(5(D 2 +D 1 ) 5 ) + ] PARAMETERS: y = Deflection of pole at point of application of load P (inches) P = Transverse load applied to pole (lbs) E = Modulus of Elasticity (29,000,000 psi) = t = Wall thickness of pole (inches) L = Length of pole above anchor plate (inches) La = Length of pole above anchor plate to point of application of load (inches) Db = Diameter at base (inches) Dt = Diameter at top (inches) D 2 = Db-t = Outside diameter of pole at anchor plate minus wall thickness (inches) D 1 = (Db-(Db-Dt)*La/L)-t = Outside diameter of pole at point of application of load P minus wall thickness (inches)

9 Pole L Db Dt t P La D Type 2 D 1 y(p) y(2/3*p) Adjusted y(2/3*p) 1 727N N N Adjusted y(2/3)*p = 1.10 * [y (2/3)*P] PART 3 EXECUTION NOT USED END OF SECTION