Attachment A3 - Special Provision.pdf

12SP-807A-02

MICHIGAN

DEPARTMENT OF TRANSPORTATION

SPECIAL PROVISION

FOR

ADJUSTING OR RECONSTRUCTING GUARDRAIL

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a. Description. This work consists of reconstructing guardrail when called for on the plans includes placing existing steel beams and certain existing fittings on new or existing posts. The work of adjusting guardrail when called for on the plans includes adjusting the height of rail on existing posts. Ensure all work is completed in accordance with section 807 of the Standard Specifications for Construction, except as stated in this special provision, as shown on the plans or in the contract, and as directed by the Engineer.

b. Materials. Provide beam elements, anchorages and fittings that have a galvanized surface finish.

Use existing beam elements and guardrail approach terminals for reconstructing guardrail provided that these materials are reusable in their present condition (unbent, galvanized, rust free, proper radius if curved rail). Ensure existing guardrail approach terminals used for reconstructing guardrail meets current standards. Re-use existing posts, offset/spacer blocks, and wood blockouts in good condition, as determined by the Engineer, for reconstructing guardrail. Do not import old posts, beam elements, offset/spacer blocks, or wood blockouts from outside the project for incorporation into this work.

If the quantities of reusable beam elements or curved beam elements of the proper radius are insufficient to complete the reconstructing beam guardrail called for, furnish additional new elements, posts, bolts, reflectors, offset blocks, spacer blocks, wood blockouts, and other pertinent fittings and install at the contract unit price for the applicable new guardrail or curved guardrail pay items. If existing guardrail approach and departing terminals do not meet current standards, furnish and install new standard terminals at the contract unit price for new guardrail approach terminals and departing terminals, respectively. If existing guardrail anchorages do not meet current standards, furnish and install new guardrail anchorages at the contract unit price for new guardrail anchorages.

Unless otherwise specified, conform to the post length specified in Standard Plan R-60 Series for reconstructing beam guardrail and guardrail post furnished and installed.

The requirements of subsection 908.12 of the Standard Specifications for Construction do not apply to reused elements and fittings from the project. However, these requirements do apply to all new rail elements, terminals, hardware, and fittings furnished for the contract.

Ensure new posts furnished for the work meets the requirements of section 912 (for wood) or 908 (for steel) of the Standard Specifications for Construction.

Ensure new offset blocks, spacer blocks, and wood blockouts meets the requirements of section 912 of the Standard Specifications for Construction.

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c. Construction.

1. Disassemble the existing guardrail beam elements and stockpile the reusable beams.

Remove concrete anchor blocks at the end of turned-down guardrail anchorages, and concrete footings for old guardrail cable anchorages.

Take ownership of unusable posts, beam elements and hardware and excess reusable beam elements and hardware, unless otherwise specified on the plans, and remove from the project.

Dismantle, separate, and stockpile beam elements and endings designated as property of the Department at an approved location(s) on the project for eventual pick up by the Department or local agency forces.

2. For standard guardrail, drill new 3/4 inch by 2½ inch post bolt slots in the beam elements, if necessary, at 6 foot 3 inch intervals (3 foot, 1½ inch and/or 1 foot, 6¾ inch spacing’s where indicated).

3. For W-beam backed guardrail and long span guardrail, drill new slots in the beam elements as needed. Applicable criteria from Standard Plan R-72 Series applies.

4. For a thrie-beam retrofit, drill new slots in the beam elements as needed. If necessary, drill new holes in the bridge railing for anchoring the guardrail. Applicable criteria from Standard Plan B-22 and B-23 Series, respectively, apply.

5. For a guardrail anchorage, drill new slots in the beam elements as needed. If necessary, drill new holes in the bridge railing, concrete barrier, or other concrete structure for anchoring the guardrail. Applicable criteria from Standard Plan R-67, R-71, B-22, and B- 23 Series, respectively, apply.

6. Repair zinc coating on beam elements, steel posts, and fittings damaged in transporting, handling, or erection. Apply zinc coating to bare metal surfaces after drilling holes/slots on beam elements. Repair zinc coating according to subsection 716.03.E of the Standard Specifications for Construction.

7. Re-erect the reusable beams on new or existing posts and offset/spacer blocks at the required spacing. Install the face of the rail at the specified distance from the edge of pavement.

8. Re-erect standard guardrail as specified on Standard Plan R-60 Series, and re-erect sections of W-beam backed guardrail as specified on Standard Plan R-72 Series.

9. Re-erect thrie-beam retrofit with reusable or new beams, wood blockouts, and miscellaneous hardware, as specified on Standard Plan B-22 and B-23 Series, respectively.

10. Re-erect guardrail anchorage with reusable or new beams, offset blocks, and miscellaneous hardware, as specified on Standard Plan R-67, R-71, B-22, and B-23 Series, respectively.

11. Backfill old postholes and voids caused by removal of concrete anchor blocks and footings using approved material and compaction methods.

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12. Adjust guardrail heights as shown on Standard Plan R-60 Series. Make height adjustments in the block mounting location only. Lifting existing posts to adjust rail height is prohibited. Ensure the post bolt (for Guardrail, Type B and Guardrail, Type MGS-8) or upper post bolt (for Guardrail, Type T) is not closer than 2 inches from the top of the wood or steel post. Field drill new holes in existing post if necessary.

Make height adjustments to usable existing guardrail approach terminals by reconstruction (complete removal and reinstallation) only. Replace unusable and substandard terminals with new standard terminals.

d. Measurement and Payment. The completed work, as described, will be measured and paid for at the contract unit price using the following pay items:

Pay Item Pay Unit

Guardrail, Reconst, Type __ ....................................................................................... Foot Guardrail Post, Furn and Install, __ inch .................................................................... Each Guardrail Height, Adj .................................................................................................. Foot

1. Guardrail, Reconst, Type __ includes guardrail constructed using new or existing posts and reused beam elements of the type specified, measured by length in feet along the face of the rail, including reused existing terminals. The work includes all materials, labor, and equipment required for:

A. Removal of existing guardrail, w-beam backed guardrail, guardrail approach terminals, guardrail departing terminals, thrie-beam retrofits, and guardrail anchorages.

B. Furnishing, as necessary, new posts, offset blocks, spacer blocks, wood blockouts, bolts, reflectors, and other pertinent fittings.

C. Backfilling old postholes.

D. Field drilling beam elements and repairing damaged galvanized surfaces.

E. Drilling holes in bridge railings, concrete barriers, and other concrete structures.

F. Transporting beam elements within the project limits.

G. Dismantling, separating and stockpiling elements and disposing of waste or scrap material.

Curved beam guardrail, if constructed of reused material, will be included as regular Guardrail, Reconst, Type __ and will not be paid for separately.

If the Engineer directs that an occasional beam element be replaced in a run being measured as Guardrail, Reconst, Type __, such removal and replacement will be considered as part of Guardrail, Reconst, Type __ if the effective length (6 foot 3 inches, 12 foot 6 inches, 25 foot, etc.) of the rail replacement does not exceed five percent of the length of that run of guardrail. If the beam replacement exceeds five percent, all of the beam removal and replacement in that run will be measured and paid for separately.

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Reconstructed guardrail anchorages will be paid for as Guardrail, Reconst, Type __ when rebuilt with existing beam elements. Otherwise, guardrail anchorages constructed with all new components will be paid for as Guardrail Anch, Bridge, Det __ or Guardrail Anch, Median.

Reconstructed thrie-beam retrofit will be measured and paid for as Guardrail, Reconst, Type __ when rebuilt with existing beam elements. Bridge Railing, Thrie Beam Retrofit will be paid for separately if it is necessary for the Contractor to furnish new thrie-beam retrofit installations due to insufficient quantities of reusable elements available on the project.

Reconstructed w-beam backed guardrail and long span guardrail will be measured and paid for as Guardrail, Reconst, Type __ when rebuilt with existing beam elements. Guardrail, Backed, Det __, of the type specified, will be paid for separately if it is necessary for the Contractor to furnish new w-beam backed guardrail installations due to insufficient quantities of reusable elements available on the project. New long span guardrail, of specified detail type, will be paid for separately with other pay item(s), as specified in the contract documents or as specified by the Engineer, if it is necessary for the Contractor to furnish new long span guardrail installations due to insufficient quantities of reusable elements available on the project.

Reconstruction of reusable existing guardrail approach and departing terminals that meet current standard will be measured and paid for as Guardrail, Reconst, Type __.

Payment for removal of existing buried ends is included in the item of Guardrail, Reconst, Type __. Where only the existing terminal or anchorage is removed in a run that is otherwise not reconstructed, the removal will be paid for as Guardrail, Rem.

2. Installing posts within existing guardrail post intervals to modify the guardrail will be measured as units of Guardrail Post, Furn and Install, __ inch of the post length specified.

The pay item includes furnishing and installing posts, offset blocks, bolts, and necessary fittings.

3. Guardrail Height, Adj will be measured in feet along the face of the rail adjusted and includes all necessary field drilling of existing posts. Pay quantities will be in increments of the post spacing called for on the plans, excluding anchorages and end shoes.

Guardrail Approach Terminal, Type __, of the type specified, will be paid for separately when required to replace unusable or substandard existing approach terminals. Guardrail Departing Terminal, Type __, of the type specified, will be paid for separately when required to replace unusable or substandard existing departing terminals.

Guardrail, Type __ and Guardrail, Curved, Type __ of the type specified, will be paid for separately if it is necessary for the Contractor to furnish new beam elements due to insufficient quantities of reusable elements available on the project.