705.01 696 SECTION 705 – GUARDRAIL
705.01 Description ................................ ................................ ................... 696
705.02 Materials ................................ ................................ ...................... 696
705.03 Reserved ................................ ................................ ....................... 697
705.04 Prelimin ary Work ................................ ................................ ......... 697
705.05 Posts ................................ ................................ ............................. 697
705.06 Installation of Posts ................................ ................................ ...... 697
705.07 Erection ................................ ................................ ........................ 699
705.08 Final Cleanup ................................ ................................ ............... 699
705.09 Me thod of Measurement ................................ .............................. 699
705.10 Basis of Payment ................................ ................................ .......... 700
DESCRIPTION
705.01 Description
This work consists of furnishing and erecting guardrail, and constructing anchor blocks and approach ends, of the specified kind and dimensions. Guardrail includes appurtenant materials and work required to make connections with other guardrail or structures, as may be required to complete the Work shown on the Plans. MATERIALS
705.02 Materials
Provide materials as specified in: Metal Beam Guardrail ................................ ............................ 909.05 Guardrail Posts ................................ ................................ ....... 909.07 Guardrail Hardware ................................ ............................... 909.08 Use Class A Portland cement concrete. Mix, place, finish, and cure concrete as specified in 604. 705.03 697 For all guardrail safety end treatment systems , provide certification from the supplier that the device meets the requirements of and is listed on the Department’s QPL or Standard Drawings. In addition, submit detailed shop drawings for the QPL or Standard Drawing approve d devices to the Engineer, and utilize a copy onsite during installation.
705.03 Reserved
CONSTRUCTION REQUIREMENTS
705.04 Preliminary Work
Perform Clearing and Grubbing, Removal of Structures and Obstructions, Excavation and Undercutting, and Embankment Construction as specified in 201, 202, 203, and 205, respectively.
705.05 Posts
Provide posts of the shape, size, and dimensions shown on the Plans and/or the approved Shop Drawings. Set posts reasonably true to the lines and grades shown on the Plans or established by the Engineer.
705.06 Installation of Po sts
Before beginning any excavation or driving any guardrail post, determine the location of all underground electrical, drainage, and utility lines in the vicinity, and conduct work so as to avoid damaging these facilities. Dig or drill holes to the depth shown on the Plans and/or the approved Shop Drawings and to a size that will allow proper setting of the posts and sufficient roo m for backfilling and tamping. Alternatively, the Contractor may drive posts using approved methods and equipment, provided the posts are erected in the proper position and are free of distortion, burring, or other damage. If solid rock is encountered while drilling post holes:
1.Within 18 inches of the ground surface, drill an oversized or elongated hole 24 inches into the rock. Set the post at the roadside edge of the hole, and backfill the hole with the cutting spoils. 705.06 698 a. If using wooden posts, either drill a single oversized hole 23 inches in diameter, or three overlapping holes 10 inches in diameter, to a length of 23 inches.
b.For steel posts, drill a single oversized hole, 20 inches in diameter, or three overlapping holes 8 inches in diameter, to a length of 20 inches.
2.Below 18 inches of the ground surface, drill holes 12 inches into the rock or to the depth shown on the Plans. The holes shall be 8 inches in diameter for steel posts, and 12 inches in diameter for wood posts.
3.When installing end terminals using tubes, install posts 1 and 2 to full depth or a minimum of 36 inches into the solid rock. Backfill the holes around the steel tube with the cutting spoils.
4.See approved shop drawings for additional i nformation concerning post depth and hole size. To validate proper installation of posts, for each guardrail contractor/installer doing work for the Department , the Regional Operations and Materials and Tests offices may select any post for verification. If the posts are found to be in accordance with the Plans and Specifications, the Contractor may re-install the posts if they were not damaged during the pulling process. If the post length is found to be deficient, the Department will require the contractor/installer to remove the entire run of guardrail or end terminal and replace it properly at no cost to the Department . Backfill holes with selected earth or other suitable materials in layers not to exceed 4 inches in thickness. Thoroughly tamp each layer. After backfilling and tamping is complete, hold the posts or anchors securely in place. For metal divider guardrail on bridges, bolt posts to the structure as shown on the Plans. Set the anchor bolts to the proper location and elevation, with templates, and carefully check after the median is placed and before the concrete has set. Set anchor bolts for metal divider guardrail, to be placed on a previously constructed bridge, by drilling holes in the proper locations and anchoring the bolts as shown on the Plans. Repair damaged coating on galvanized steel posts as specified in 713.04.B , or replace the posts, at the Engineer’s direction, at no cost to the Department. 705.07 699 705.07 Erection Set guardrail anchors, and make and place attachments as shown on the Plans and/or approved Shop Drawings, or as directed by the Engineer. Guardrail installed on new alignments is to be complete in place before the mainline roadway is opened to traffic unless otherwis e directed by the Engineer. On roadways open to traffic, install each section of guardrail complete in place including end sections in a continuous operation. Draw up tightly all bolts or clips used for fastening the guardrail or fittings to the posts. E nd bolts shall have sufficient length to extend at least ¼ inch through and beyond the full nut, except where such extension might interfere with or endanger traffic, in which case, cut off the bolt flush with the nut. Erect, draw, and adjust all railings so that the longitudinal tension will be uniform throughout the entire length of the rail. Shop curve Metal Deep Beam Single Guardrail and Protective Guardrail at Bridge Ends that are installed on a curve with a radius of 150 feet or less.
705.08 Final Cleanup
Perform final cleanup as specified in 104.10. COMPENSATION
705.09 Method of Measurement
The Department will measure Guardrail of the various classes and dimensions in accordance with the Plans. The Department will measure Terminal Anchors of the various types for payment by the unit within the limits shown on the Plans. The Department will not measure projections or anchors beyond the end post for payment, except as noted. The Department will consider excavation and backfilling, and the furnishing and placing of anchor bolts and devices for guardrail posts on bridges, to be incidental to the work. 705.10 700 705.10 Basis of Payment The Department will pay for accepted quantities, complete in place, at the contract prices as fo llows: Item Pay Unit Guardrail (Class) Linear Feet Guardrail End Terminal (Type) Each Single Guardrail (Type) Linear Feet Guardrail at ______ Linear Feet The Department will make no payment for a section of guardrail, including end terminals, until it is complete in place. Payment is full compensation for all posts, blocks, rail elements, terminal sections, fittings, hardware, labor and equipment, and all incidentals necessary to complete the work. When no contract unit price has been established for Sh op Curved Metal Deep Beam Single Guardrail, payment will be made at a rate equal to 1.5 times the contract unit price for Metal Deep Beam Single Guardrail with corresponding post spacing. When no unit price has been established for Shop Curved Protective Guardrail at Bridge Ends, payment will be made at a rate equal to 1.25 times the contract unit price of Guardrail at Bridge Ends. No additional payment will be made for shop curving the guardrail in the Guardrail End Terminal units. When no contract unit p rice has been established for d rilling or boring in solid rock for posts while placing Single Guardrail or End Terminal Posts , the Department will pay for each hole at a rate equal to 2.0 times the contract unit price for Single Guardrail. When no pay item for Single Guardrail exists in the Contract, payment will be made at a rate of 2.0 times the current yearly State average. While drilling or boring i nto solid rock for posts placed in conjunction with Guardrail at Bridge Ends, Parapets, Piers, Concrete Endposts, and other similar edifice, payment will be made at a rate equal to 1.25 times the contract unit price per applicable end device . No additiona l payment will be made for drilling or boring for the placement of posts, unless posts are driven to refusal in solid rock . 706.01 701 SECTION 706 – GUARDRAIL ADJUSTED, REMOVED AND RESET
706.01 Description ................................ ................................ ................... 701
706.02 Materials ................................ ................................ ...................... 701
706.03 Reserved ................................ ................................ ....................... 702
706.04 Preliminary Work ................................ ................................ ......... 702
706.05 Dismantling or Removing Guardrail ................................ ............ 702
706.06 Installation of Posts ................................ ................................ ...... 703
706.07 Erection ................................ ................................ ........................ 703
706.08 Guardrail Adjustment ................................ ................................ ... 703
706.09 Final Cleanup ................................ ................................ ............... 703
706.10 Method of Measurement ................................ .............................. 703
706.11 Basis of Payment ................................ ................................ .......... 704
DESCRIPTION
706.01 Description
Guardrail Adjusted or Removed and Reset consists of dismantling, removing, salvaging, resetting, or adjusting existing guardrail, as shown on the Plans or as directed by the Engineer. The work includes the furnishing of all necessary hardware, anchors, and other appurtenances required to replace those that are not suitable for reuse. Posts Furnished and Guardrail Furnished consists of furnishing and setting guardrail and posts to replace rail and posts that are unsuitable for resetting, as shown on the Plans or as directed by the Engineer. Guardrail remove d and reset shall comply with the Department’s Standard Drawings and/ or approved Shop Drawings, as applicable for the type of installation. MATERIALS
706.02 Materials
Provide materials as specified in: Guardrail Posts ................................ ................................ ....... 909.07
Source: Tennessee Standard Specifications for Road and Bridge Construction, 2021 Edition. Pages 705–709 of 1,072.