Article 1 — Description
Installation . Furnish, fabricate, and erect overhead sign supports . Relocation . Remove and relocate existing overhead sign supports . Removal . Remove existing overhead sign supports .
Article 2 — Materials
Provide new materials that comply with the details shown on the plans, the requirements of this Item, and the pertinent requirements of the following Items . Item 416, “Drilled Shaft Foundations” Item 420, “Concrete Substructures” Item 421, “Hydraulic Cement Concrete” Item 441, “Steel Structures” Item 442, “Metal for Structures” Item 445, “Galvanizing” Item 449, “Anchor Bolts” Item 618, “Conduit” Furnish alloy steel or medium- strength mild steel anchor bolts in accordance with Section 449.2.1., “Bolts and Nuts,” unless otherwise shown on the plans. Furnish galvanized steel, non- corroding stainless steel, or dichromate- sealed aluminum brackets, clamps, bolts, and other hardware, in accordance with DMS -7120 , “Sign Hardware.” Reuse undamaged components when relocating an existing overhead sign structure. Provide new components to replace any damaged during removal or relocation, in accordance with the Items listed in this Article, unless otherwise directed.
Article 3 — Construction
3.1 Alternate Design . Alternate designs of monotube overhead sign supports are not permitted. The
Department will consider alternate designs for cantilevered-truss type overhead sign support columns that meet the requirements of this Item and the plans. Submit design calculations and a list of proposed materials, including anchor bolts, before submitting shop drawings. Additionally, submit relevant plans such as Cantilever Overhead Sign Supports (COSS) plan and elevation sheets, COSS & OSB -SZ table sheets, and any other sheets to support the design calculations. Computer- generated design parameters and calculations are not acceptable unless accompanied by the appropriate supporting documentation. Determine the pipe diameter and wall thickness to be used for the column from the appropriate COSS or High Level Cantilever Overhead Sign Supports (HCOSS) standard plan tables for the height and span shown on the plans. Determine the maximum design parameters from the COSS or HCOSS standard plan tables for that pipe diameter and wall thickness . Ensure alternate designs meet or exceed these maximum design parameters. Provide top column dimensions compatible with the sign truss mounting details. Ensure bottom diameter of the column is compatible with foundation details. 891 Limit welds to two longitudinal seam welds per column. Provid e full penetration longitudinal seam welds within 6 in. of circumferential welds, and 85% minimum penetration seam welds at other column locations. Provide longitudinal seam weld and fit -up that will minimize acid entrapment during later galvanizing. Taper ed columns are permitted if the provided calculations demonstrat e that the column is adequate at the level of the truss -to-column connection.
3.2 Shop Drawings . Electronically submit shop drawings for overhead sign supports in accordance with
Item 441. Include details for anchor bolts, highway and dynamic message sign sizes and positions, walkways, and other required attachments on shop drawings. Submit only one drawing for two or more supports of identical design and dimensions.
3.3 Fabrication . Fabricate and weld in accordance with Item 441, AWS D1.1, and this Item.
Fabrication plants that produce overhead sign support structures must be approved in accordance with DMS -7380 , “Steel Non- Bridge Member Fabrication Plant Qualification.” The Materials and Tests Division maintains an MPL of approved overhead sign support structure fabrication plants. For monotube- type overhead sign supports fabricated with seam -welded pipe, locate the longitudinal seam weld at the neutral axis during the bending process of the post. For cantilevered- truss type overhead sign support columns with diameters exceeding 30 in., one circumferential weld splice is permitted per column. Locate the splice at a minimum height of 1/2 the column length. Provide mounting channels for the installation of traffic control devices unless otherwise shown on the plans. Provide 100% ultrasonic testing (UT) in accordance with AWS D1.1 on all circumferential butt joint weld splices of monotube- type posts and cantilevered truss -type columns. UT acceptance- rejection criteria must be in accordance with AWS D 1.1 for cyclically loaded nontubular connections in tension. For alternate design cantilevered- truss type overhead sign support columns, perform at least 10% UT on longitudinal seam welds using a Department -approved procedure to ensure minimum specified penetration. Perform testing at a minimum of three locations on each column (top, middle, and bottom). The minimum length of each test area will be 10 in. If minimum specified penetration is not achieved in any of the tested areas, test an additional 24 in. beyond the originally selected test area or areas requiring the specified minimum penetration. Test the entire column seam weld if any location within the additional 24- in. test area or areas does not achieve the specified minimum penetration. Repair the deficient areas using a Department -approved repair procedure and retest. Measure required dimensions of truss -type overhead sign support structures, including camber of overhead sign bridge trusses (in vertical position) and rise of cantilever overhead sign support trusses (in horizontal position). Shop assemble monotube- type overhead sign supports in the horizontal position to ensure specification compliance for all required dimensions, alignment, geometry, and fit. Permanently mark sign support base plates with the fabrication plant’s insignia. For monotube- type supports, place the mark on the base plate adjacent to the hand hole access compartment . Conformance to plans and other approved drawings does not relieve the Contractor of responsibility for proper fit of components. 892 3.4. Galvanizing . Provide punched, drilled, or mechanically guided thermal cut holes in steel parts or members , when allowed, before galvanizing. Mechanically guided thermal -cut hole quality will be in accordance with Item 445. Hot -dip galvanize all fabricated parts in accordance with Item 445.
3.5 Galvanizing Repair . Repair galvanizing for steel parts or members damaged in assembly, transit, or
erection; for permitted field- drilled holes; or for steel parts or members welded after galvanizing in accordance with the pertinent requirements of Section 445.3. 4., “Repairs.”
3.6 Installation . Stake sign support locations for verification by the Engineer. Install overhead sign support
structures at verified locations. Use established industry and utility safety practices when erecting sign supports near overhead or underground utilities. Consult with appropriate utility companies before beginning work. Construct concrete overhead sign support columns, spans, or both as shown on the plans and in accordance with Item 420. Construct foundations for new overhead sign supports in accordance with Item 416 and as shown on the plans. Orient anchor bolts as shown on the plans. Cap conduit before concrete placement. Ensure the anchor bolt and template ass embly is held in position during concrete placement. Use bracing attached to the upper template to ensure conduit is held in place during concrete placement. Remove top template after the concrete achieves initial set. Erect structures after foundation concrete has attained its design strength as shown on the plans and in accordance with Item 421. Coat anchor bolt threads and tighten anchor bolts in accordance with Item 449. Ensure that the structure is plumb. Do not use springing or raking of columns, towers, or anchor bolts to achieve plumb. Tack weld each anchor bolt nut to its washer in two places and tack weld each washer to the base plate in two places after the overhead sign support has been plumbed and all nuts are tight. Tack weld in accordance with Item 441, AWS D1.1, and this Item . Do not weld components to the bolt. Repair galvanizing damage on bolts, nuts, and washers after tack welding in accordance with Section 445.3. 4., “Repairs.” Do not grout between the base plate and foundation. Ensure sign faces are vertical .
3.7 Relocation . Disconnect and isolate electrical power supplies before removing the structure. Remove existing
overhead sign support structures as directed. Ensure the structures or attached components suffer no undue stress or damage. Si gns, sign walkways, mounting brackets, etc., may be left on the structures, unless otherwise shown on the plans or as directed. Repair or replace damaged components as directed. Remove abandoned concrete foundations and replace surfacing in accordance with Section 650.3.8., “Removal,” unless otherwise shown on the plans . Move existing overhead sign supports to locations shown on the plans or as directed. Construct foundations for relocated overhead sign supports in accordance with Item 416 and as shown on t he plans. Install existing structures on new foundations in accordance with Section 650.3.6., “Installation.” Never reuse or replace lighting materials. Reuse other existing components, with the exception of conductors, unless otherwise directed. Accept ow nership and dispose of unsalvageable materials in conformance with federal, state, and local regulations.
3.8 Removal . Disconnect and isolate electrical power supplies before removing the structure. Remove sign
panels, walkways, lighting fixtures, lighting brackets, ballast boxes, and other accessories from overhead sign supports. Remove and store items designated for reuse or salvage at locations shown on the plans or 893 as directed. Store sign panels above the ground in a vertical position. Accept ownership and dispose of unsalvageable materials in conformance with federal, state, and local regulations. Remove abandoned concrete foundations, including steel, to 2 ft. below finished grade unless otherwise shown on the plans. Cut off and remove steel protruding from the remaining concrete. Backfill with material equal in composition and density to the surrounding area and replace surfacing with like material to an equivalent condition.
Article 4 — Measurement
This Item will be measured by each overhead sign support installed, relocated, or removed.
Article 5 — 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 “Install Overhead Sign Supports” of the type and span lengths specified, “Relocate Existing Overhead Sign Supports,” and “Remove Overhead Sign Supports.” The span lengths will be the design span lengths shown on the plans rounded up to the next 5- ft. increment. New drilled shaft foundations will be paid for under Item 416. New concrete columns and spans will be paid for under Item 420. New signs will be paid for under Item 636, “Signs.” New sign walkways will be paid for under Item 654, “Sign Walkways .”
5.1 Installation . This price is full compensation for furnishing, fabricating, galvanizing, assembling, and erecting
the overhead sign supports; furnishing and placing anchor bolts, nuts, washers, and templates; furnishing and placing conduit, ground rods, and wiring; and materials, equipment, labor, tools, and incidentals.
5.2 Relocation . This price is full compensation for removing overhead sign supports; removing existing
foundations; backfilling and surface placement; storing the components to be reused or salvaged; disposal of unsalvageable materials; furnishing, fabricating, and installing required new components , including anchor bolts, nuts, washers, and templates; placing and securing sign supports on new foundations; furnishing and placing conduit, ground rods, and wiring; loading and hauling; and materials, equipment, labor, tools, and incidentals.
5.3 Removal . This price is full compensation for removing overhead sign support components; removing the
foundations; storing the components to be reused or salvaged; disposal of unsalvageable materials; backfilling and surface placement; loading and hauling; and materials, equipment, labor, tools, and incidentals.