Read PART I, GENERAL REQUIREMENTS AND COVENANTS text version

HIGH MAST ILLUMINATION POLES

ITEM 613

CITY OF ABILENE ITEM 613 HIGH MAST ILLUMINATION POLES

613.1 DESCRIPTION.

This Item shall govern for designing, fabricating, furnishing and erecting high mast illumination poles of the design, wind speed, and heights as shown on the Plans.

613.2 GENERAL.

All materials and construction methods shall conform to the requirements of this Item and the pertinent requirements of the following Items: TxDOT Item 416, "Drilled Shaft Foundations" Item 432, "Riprap" TxDOT Item 441, "Steel Structures" TxDOT Item 442, "Metal for Structures" TxDOT Item 445, "Galvanizing" TxDOT Item 449, "Anchor Bolts" TxDOT Item 614, "High Mast Illumination Assemblies" Item 618, "Conduit" Item 624, "Ground Boxes"

613.3 STANDARD POLE DESIGNS.

Shop drawings shall not be required or submitted for high mast illumination poles fabricated in accordance with this Item and the details shown on the Plans. Any deviation from the Plans will require submission of shop drawings of the complete pole structure, including anchor bolts, in accordance with TxDOT Item 441, "Steel Structures". Deviations, which affect the basic structural behavior of the pole, will be considered as optional pole designs.

613.4 OPTIONAL POLE DESIGNS.

Optional pole designs shall be subject to the following requirements and shall meet all other requirements of this Item. Optional pole designs shall conform to the AASHTO STANDARD SPECIFICATIONS FOR STRUCTURAL SUPPORTS FOR HIGHWAY SIGNS, LUMINAIRES, AND TRAFFIC SIGNALS. Two (2) sets of complete design calculations shall be submitted for approval prior to submission of shop drawings. Computer printouts for design calculations will not be acceptable unless accompanied by sufficient documentation, which demonstrates methods used. Unless otherwise shown on the Plans, the design calculations and six (6) sets of shop drawings shall be submitted to the Director of Bridges and Structures, TxDOT, 125 East 11th St., Austin, Texas 78701-2483. The applied design loads at the top of the poles shall be as given in the following table. These values include the gust multiplier and the drag and height coefficients.

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ITEM 613

HIGH MAST ILLUMINATION POLES

Pole Height Ft. 100 125 150 175

Basic Design Wind Speed 80 mph 100mph Vert (Lbs) Horiz (Lbs) Vert (Lbs) Horiz (Lbs) 1800 2240 1800 3500 1800 2240 1800 3500 1800 2240 1800 3750 1800 2240 1800 3750

Additional design loads on the pole shaft shall include shaft dead load and appropriate wind drag and height coefficients with the standard wind gust multiplier. The maximum design yield strength for anchor bolts shall be 55 ksi. The maximum design yield strength for ASTM A572 materials shall be 50 ksi. The top pole diameter and the top attachment plate shall be as shown on the Plans. The bottom of the pole shall be compatible with the foundation details shown on the Plans. The design shall be such that the standard mounting ring and lowering mechanism can be used without modification. The spacing, size and number of anchor bolts may be changed. The anchor bolt circle shall be such that the bottom template does not conflict with foundation reinforcement. The minimum nominal splice length of pole shaft sections shall be 1.5 multiplied by the average pole diameter at the splice to the nearest inch. The average diameter shall be taken at the interface between the sections at half splice length. Approval to eliminate the ground sleeve or to significantly modify the access hole ring shall require testing a full-scale specimen of the base section. The specimen shall be supported at the base plate on double nutted anchor bolts. The specimen shall be loaded to produce maximum compression on the access hole ring. The test results shall clearly demonstrate that the specimen can develop the factored moment capacity (1.38 load factor multiplied by 1.4 wind factor multiplied by Fb) which is approximately the full plastic bending capacity.

613.5 MATERIALS.

Metal used shall conform to TxDOT Item 442, "Metal for Structures", except for measurement and payment, and the additional requirements as follows: Pole Shafts Ground Sleeves ASTM A588, A572 Grade 50 (1), or A607 Grade 50 Class 2 (2) ASTM A588, A572 Grade 50 (1), A607 Grade 50 Class 2 (2), or A633 Grade C (1) ASTM A588, A572 Grade 50 (1), A633 Grade C (1), or A36M50 (3) ASTM A588, A572 Grade 50 (1), A633 Grade C (1), or A36M50 (3) ASTM A36 or equal

Base Plates (4) Access Hole Rings Miscellaneous Steel

(1) ASTM A572 and A633 materials may have higher yield strengths but shall not have less elongation than the grade indicated. (2) ASTM A607 is acceptable to a maximum thickness of 0.50 inch.

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HIGH MAST ILLUMINATION POLES

ITEM 613

(3) A36M50 is a special designation for a modified ASTM A36 material with a higher specified yield strength and meeting the additional requirements described in TxDOT Item 442, "Metal for Structures". (4) An ultrasonic examination in accordance with either ASTM A578 Level II or ASTM A435 shall be conducted for all material used for base plates. All the above steel, greater than 0.50 inches thick, except miscellaneous steel, shall conform to the longitudinal Charpy V-notch requirements of ASTM A572, Group 1, in accordance with Article 442.3. The silicon content of all steel shall be controlled to ensure high quality galvanizing and to avoid discoloration. Unless otherwise shown on the Plans, anchor bolts shall be alloy steel or medium-strength, mild steel as described in TxDOT Item 449, "Anchor Bolts". All materials furnished by the Contractor shall be new.

613.6 FABRICATION.

Fabrication and welding shall be in accordance with TxDOT Item 441, "Steel Structures", the ANSI/AWS STRUCTURAL WELDING CODE D1. 1, the details shown on the Plans and the requirements of this Item. All pole shaft sections shall be match-marked as shown on the Plans. Conformance to the Plans and/or other approved drawings does not relieve the Contractor of the responsibility for providing proper fit of components.

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ITEM 613

HIGH MAST ILLUMINATION POLES

Fabrication Tolerances: Part Pole Shafts Dimension Length (unassembled sections), Shaft thickness (1) I.D. of outside slip fitting O.D. of inside slip fitting Difference between flats or dia Straightness Attachment locations Perpendicular to base plate Shaft centered on base plate Twist in shaft (2) Position of winch channel Overall Thickness Deviation from flat Spacing between holes Bolt hole size Outside diameter Inside diameter Thickness Spacing between holes Bolt hole size Length Threaded Length Galvanized Length Bolt hole spacing Tolerance (Inches) + /-1 + 0.12-0.02 + 1/8 - 1/16 + 1/32 - 1/8 + /- 1/4 1/8 in 10 ft + /- 1 1/8 in 24 + /- 1/4 4 deg in 100 ft + /- 1/4 + /- 1/4 + 1/4 - 1/16 3/16 in 24 + /- 3/16 +/- 1/16 + /- 1/8 +1-1/4 + 1/4 - 1/32 +/- 1/16 +/- 1/16 +/- 1/2 + /- 1/2 - 1/4 +/- 1/16

Assembled Pole Shafts

Base Plates

Anchor Bolt Templates

Anchor Bolts

Misc.

(1) Shaft thicknesses in excess of +0.02 inches over the nominal thicknesses may require adjustments of the pole diameters. Changes in splice lengths may also be necessary. (2) Individual pole sections with excessive twist will be acceptable, provided the assembled match-marked sections maintain the top of the pole within the twist tolerance. Circumferential welds will be permitted only at the top attachment and base plates. Longitudinal seam welds that will be in contact with an outer or inner section at a slip joint splice shall be ground or otherwise smoothed to the same radius as other shaft corners for the length of the splice plus a minimum of six (6) inches. Seam welds of the remainder of the exterior of the pole sections shall be within acceptable weld profiles. Longitudinal seam welds in outer sections at splices and at base plates shall have 100 percent penetration for 1.5 pole diameters plus a minimum of six (6) inches. All other longitudinal seam welds for pole sections shall have 85 percent minimum penetration. Welding of longitudinal seams shall be done in a manner that will minimize acid entrapment during later galvanizing.

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HIGH MAST ILLUMINATION POLES

ITEM 613

The fabricated pole sections and associated parts shall be hot-dip galvanized in accordance with TxDOT Item 445, "Galvanizing". Any holes in steel parts or members that may be permitted by the Plans or by the Engineer shall be punched or drilled before the parts or members are galvanized. Any steel part or member on which galvanizing has been damaged in assembly, transit or erection and any steel part or member welded after galvanizing shall be repaired in accordance with TxDOT Item 445, "Galvanizing".

613.7 CONSTRUCTION METHODS.

High mast illumination poles shall be located as shown on the Plans, except that the Engineer may shift the poles, within design guidelines, where necessary to secure a more desirable location or to avoid conflict with utilities. Unless otherwise shown on the Plans, the Contractor shall stake and the Engineer will verify all pole locations. Erection of poles near any overhead or underground utilities shall be accomplished using established industry and utility safety practices. The Contractor shall consult with the appropriate utility company prior to beginning such work. Foundations shall be constructed in accordance with TxDOT Item 416, "Drilled Shaft Foundations", and the details shown on the Plans. Anchor bolts shall be placed in the foundation so that there are always two (2) bolts on the reference line as shown on the Plans. Riprap around pole foundations shall be in accordance with Item 432, "Riprap", and the details shown on the Plans. Anchor bolts and templates shall be rigidly held in position during concrete placement. The top template may be removed after the concrete has achieved initial set. Conduit shall be held in place with the bar attached to the upper template and shall be capped prior to placing concrete. Conduit shall be reamed to remove burrs and sharp edges. Bell ends or bushings shall be installed on the conduit. Poles shall be assembled on blocking using a minimum of two (2) hydraulic rams at the splices. The free end of the section being assembled shall be supported by hoist equipment. All assembly force shall be applied by the hydraulic rams, which shall be of sufficient capacity to properly draw the sections together with little or no remaining gaps. Splices shall be assembled to a minimum of 90 percent or a maximum of 110 percent of the Planned lap. Splices, which do not meet lap tolerances, will require approval by the Engineer in writing. Threads of anchor bolts shall be coated with pipe joint compound prior to installation of nuts when erecting pole. Poles shall have an erection tolerance of 12 inches from vertical. During erection of the pole the Contractor shall use sufficient temporary slings, chains or wire rope to prevent unintentional separation of the pole sections. Lower anchor bolt nuts shall be retighted against the base plate after the upper nuts are tight. A slug wrench and sledge are recommended for tightening nuts. After the pole has been plumbed and all nuts are tight, each anchor bolt nut shall he tack welded in two (2) places to its washer and each washer shall be tack welded to the base plate in two (2) places. No welding is to be made to the bolt. Galvanizing in tack weld areas shall be repaired using zinc-rich paint in

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ITEM 613

HIGH MAST ILLUMINATION POLES

accordance with TxDOT Item 445, "Galvanizing". The exposed upper threads of the anchor bolts shall be cleaned of pipe joint compound and coated with zinc-rich paint to seal the bolt thread-nut joint. No grout shall be placed between the base plate and the foundation.

613.8 MEASUREMENT.

This Item will be measured as each high mast illumination pole is complete and in place.

613.9 PAYMENT.

The work performed and materials furnished in accordance with this Item and measured as provided under "Measurement" will be paid for at the unit price bid for "High Mast Illumination Poles" of the various wind designs and heights specified. This price shall be full compensation for furnishing, fabricating, galvanizing, assembling and erecting the pole upon a foundation; for furnishing and placing anchor bolts, nuts, washers and templates; for furnishing and placing conduit, ground rods and wiring as shown on the Plans; and for all other materials, labor, tools, equipment or incidentals necessary to complete the work, except as shown below. Drilled shaft foundations will be paid for under TxDOT Item 416, "Drilled Shaft Foundations". Riprap will be paid for under Item 432, "Riprap". Ground boxes will he paid for under Item 624, "Ground Boxes". Illumination assemblies will be paid for under TxDOT Item 614, "High Mast Illumination Assemblies".

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