379 SECTION 764
764.01 Description
This work consists of installing, removing, and resetting guardrail and attenuation devices.
764.02 Equipment
Reserved.
764.03 Materials
Item Section Concrete, Class AE 802 Deformed and Plain Steel Bars for Concrete Reinforcement 836.02 A Guardrail and Posts 862
764.04 Construction Requirements
A.General.
1.Installation Requirements. Before guardrail removal, installation, and extension, develop a written construction schedule for work at the guardrail location, and have the schedule reviewed by the Engineer. Include a sequence of controlling items and the timing of each in the schedule of work. Do not stop work between controlling items for more than four working days at any individual run. Install the guardrail to produce a smooth continuous line with uniform height. Set posts plumb with the front faces uniformly aligned. Backfill posts with approved material placed and compacted in 6 inch layers, using a mechanical tamper. Place hot bituminous pavement before guardrail post installation. Drill post holes for the new or reset guardrail through the hot bituminous pavement. Install the post in the remaining material by augured holes or driving. When posts are installed in augured holes, backfill the holes with approved material without displacing the post alignment. Remove surplus excavated material. When posts are driven, make the diameter of the hole in the bituminous pavement sufficient so when the soil around a post heaves up while the post is driven, the remaining asphalt will not move. If driving causes damage to posts, replace the post and install the replacement post by auguring the hole. Use a post cap if making minor vertical adjustments wi th a sledgehammer or maul. Place a maximum thickness of 2 inches of bituminous material around each post to blend the post hole into the surrounding bituminous material. Do not burn or weld after the material has been galvanized. All holes shall be machi ned drilled. Repair areas exposed by cutting or drilling and any damaged galvanized coating according to Section 854.02, “Damaged Galvanized Coatings”. Hang guardrail and end terminals for individual runs in a single day.
2.Installation on Roadways Open to Public Traffic. At locations of guardrail installation where the roadway is open to traffic, complete the installation of each individual run within 10 working days from the date all controlling items allow guardrail installation to begin. Install delineator drums, as specified in Section 704, “Temporary Traffic Control ”, at 25- foot intervals adjacent to areas meeting one of the following conditi ons: − Existing guardrail was removed and new guardrail will be installed; − Where no guardrail previously existed but will be installed; or − At guardrail extensions. Leave the drums in place until guardrail installation at that location is complete and accepted by the Engineer.
3.Failure to Comply with Installation Requirements. Provide temporary protection according to the plans at an object if unable to complete the required work in the specified time. Do not use material installed for this purpose i n the final guardrail installation. The Department will not make separate payment for attenuation provided due to the Contractor’s inability to complete the work in the specified time. If the Contractor fails to comply with all requirements of on Roadways Open to Public Traffic” , the Engineer will perform one or both of the following:
1.The Engineer will apply a contract price reduction of $1000 per day if the deficiency is not remedied within 24 hours of notification to correct the item.
2.The Engineer will have the temporary protection installed by other forces and deduct the costs from monies due or that become due to the Contractor. If the Engineer uses other forces to install temporary protections, remove and dispose of the materials installed by the other forces at no additional cost to the Department.
B.Cable Guardrail. Eliminate cable slack by over -tensioning the cable and then backing off to the required tension. Measure the required tension by achieving a 5 inch deflection by weighting a 12.5 foot span with a central load of: 200 pounds when the temperature is 100°F 220 pounds when the temperature is 80°F 381 240 pounds when the temperature is 60°F 260 pounds when the temperature is 40°F Ensure the tension of all the cables is to the same deflection throughout the length of the rail. Cast concrete anchors in place and do not disturb the earth surrounding the anchor. At locations where cable is connected to a cable socket with a wedge-type connection, crimp one wire of the wire rope over the base of the wedge to hold it firmly in place.
C.W-Beam Guardrail. Join the rail sections so the splices are lapped to flow in the direction of the traffic nearest the guardrail. Construct the lap splices so the plate ends make contact throughout the entire area of the splice. Submit a copy of the installation instructions and drawings of the guardrail end terminals. Ensure the drawings contain all components of the end tr eatment assembly.
D.Removal of Guardrail.
1.General. If the Engineer determines that the concrete anchors do not interfere with other construction, cut off concrete anchors one foot below ground level. When concrete anchors are removed, backfill the holes with approved material in 6 inch layers. Thoroughly tamp each layer using a mechanical tamper. If concrete anchors are cut off or removed, shape the surface to match the surrounding area and dispose of the removed concrete. When removing guardrail posts and not replacing the posts in the same hole, backfill the hole with approved material. When the existing surrounding surface is bituminous, place 2 inches of bituminous material at the top of the hole to match existing surrounding surface.
2.Removed Guardrail in Locations Where There will be no permanent guardrail. At locations where guardrail is to be removed and no guardrail will exist upon completion of the work, leave the guardrail in place until the hazard associated with the guardrail is no longer present and all work is complete except for that which requires the guardrail to be removed.
E.Salvaged Guardrail Materials. Disassemble rail and end treatments to be salvaged at each joint or splice.
1.Cable Guardrail. Stockpile salvaged cable in rolls.
2.Miscellaneous Hardware. Place miscellaneous hardware from the removed guardrail in containers at the stockpile site. 382 3. Disposal of Unsalvageable Materials. Remove and dispose of all damaged posts, rail, and hardware.
F.Reset Guardrail. When resetting guardrail, install the guardrail material as specified for the type of guardrail being reset. Stockpile the box beam rail removed in lengths not to exceed 36 feet. Stockpile the W-beam rail removed for reset in lengths not to ex ceed 50 feet.
G.Attenuation Devices. Install attenuating devices that meet the appropriate MASH testing Requirements and have an eligibility letter from FHWA. Install attenuating devices as specified by the manufacturer. Furnish the Engineer work drawings for crash cushions. Include manufacturer’s specifications, erection instructions, maintenance instructions and the FHWA approval letter in the shop drawing submittal.
764.05 Method of Measurement
The Engineer will measure as specified in Section 109.01, “Measurement of Quantities”.
764.06 Basis of Payment
Pay Item Pay Unit _____ Guardrail Linear Foot W-Beam Guardrail End Terminal Each Remove & Reset Guardrail Linear Foot Remove W -Beam Guardrail & Posts Linear Foot Reset W -Beam Guardrail Linear Foot Reset W -Beam Guardrail End Terminal Each Reset Box Beam Guardrail Linear Foot Remove Concrete Safety Shape Transition Each Remove 3 -Cable Guardrail & Posts Linear Foot Remove Box Beam Guardrail Linear Foot Remove Box Beam Guardrail End Section Each Barrel Attenuation Device – Type B -__ Each Attenuating Crash Cushion Test Level -__ Each The department will make payment for temporary delineator drums according to Section 704, “Temporary Traffic Control” . Such payment is full compensation for furnishing all materials, equipment, labor, and incidentals to complete the work as specified. Section 766 383 SECTION 766 MAILBOX ASSEMBLIES
766.01 Description
This work consists of removing mailbox assemblies, furnishing and installing new support systems, and fastening the removed mailboxes or new mailboxes to the new support systems.
766.02 Equipment
Reserved.
766.03 Materials
Reserved.
766.04 Construction Requirements
A.General. The mailbox owner will furnish a postal service approved mailbox. Install the furnished mailbox on the new support system.
B.Temporary Relocation. If construction activities require the removal of the support system and delayed installation of the new support system, reset the existing support system at a location approved by the Engineer and postal service. If construction activities require the removal of the support system and delayed installation of the new support system, relocate mailboxes to a location approved by the Engineer and postal service. If existing mailboxes meet NCHRP 350 or MASH requirements, they may be reset temporarily during construction. If the existing support does not meet NCHRP 350 or MASH, place temporarily located mailboxes on supports that meet MASH requirements. If there is no support that meets MASH requirements, perform one of the following actions: − Place them outside the clear zone; − Place them on a 4 × 4 inch wood post; or − Reset them using assemblies shown in the plans. After construction has progressed to allow permanent installation, install the mailbox assemblies and mailboxes at the specified locations.
766.05 Method of Measurement
The Engineer will measure as specified in Section 109.01, “Measurement of Quantities” and as follows: The Engineer will measure mailbox assemblies on a single support system as one Each.
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 414–417 of 550.