Section 265 — Roadside Rockfall Protection
Description
265.01This work consists of installing roadside rockfall protection.
Construction Requirements
265.02Qualifications. Provide an on- site supervisor with experience installing gabion barriers and flexible rockfall barrier systems, and drill operators with experience installing ground anchors. A t least 30 days before starting rockfall protection work, submit the following for approval:
(a)On-site supervisor. A résumé describing experience on at least fiv e projects installing gabion barriers and flexible rockfall barrier fence systems within the past 5 years. Include project names, locations, and contact information for project owners;
(b)Drill operators. A résumé describing experience installing at least 1000 linear feet of ground anchors for flexible rockfall barrier systems within the past 3 years. Include project names, locations, and contact information for project owners; and
(c)Manufacturer of the flexible rockfall barrier systems. Include written evidence demonstrating the manufacturer has at least 5 years ’ experience with manufacturing and supplying systems used in a similar application and capacity .
265.03Submittals. At least 30 days before starting roadside rockfall protection work, submit a work plan according to Subsection 104.06. Include the following:
(a)Evidence of certification for the flexible rockfall barrier systems according to European Assessment Document (EAD 340059-00- 0106), including performance values for energy level classification, maximum energy level (MEL), service energy level (SEL), classification for residual height for MEL, and elongation at the MEL. Include evidence no more than 1 year old from the manufacturer that the flexible rockfall barrier system supplied has been tested and verified to equal or exceed the flexible rockfall barrier system requirements as shown in the plans;
(b)A list with brochures and data sheets for system appurtenances to be used. Include the welded or twisted wire mesh for gabion barriers, and the following for flexible rockfall barrier system; mesh fabrics, anchors, support system, lacing wire rope, wire mesh fasteners, anchor bars, wire rope anchors, grout, wire rope, clips, thimbles, ferrules, steel rings, and other fastening hardware;
(c)Manufacturer’s design and detail drawings showing full, detailed dimensions of component parts and layout of posts, post anchorage systems, post foundations, anchors and support ropes, system and material specifications, and assembly plan for the flexible rockfall barrier system. Include post foundation dimensions and offset relative to centerline;
(d)Methods, equipment, and materials for preparing the alignment for the gabion barriers and flexible rockfall barrier systems;
(e)Methods, equipment, and materials for designing and installing the post anchorage systems and foundations for the flexible rockfall barrier system as required by the manufacturer. Include the construction sequence including the required curing time for foundations and anchors before installing other system components or applying external loads;
(f)A manual detailing the required flexible rockfall barrier system maintenance procedures, as specified by the manufacturer ; and
(g)Methods, materials, and equipment for drilling, installing, grouting, and testing anchors for flexible rockfall barrier system. Include the following:
(1)Mix design for grouting operations ;
(2)Manufacturer’s recommendations for anchor test loads ;
(3)Working drawings for the temporary yoke or load frame to be used for the anchor proof testing ; and (4) Calibration data performed by an independent testing laboratory within 90 days of the submittal for each load cell, test jack pressure gauge, and master pressure gauge to b e used.
265.04General. Install roadside rockfall protection at the locations and with the requirements shown in the plans. Construct roadside rockfall protection consisting of gabion barriers and flexible rockfall barrier systems as shown in the plans. Perform safety scaling that the Contractor deems necessary according to Section 262. Repair galvanized finishes according to Section 563. If applicable, treat exposed steel surfaces accordin g to Section 563. Recalibrate each load cell, test jack pressure gauge, and master pressure gauge every 90 days from the originally submitted calibration date .
265.05Gabion Barriers. Conform to 265.06 Flexible Rockfall Barrier Systems. Design, provide, and install roadside rockfall protection fences according to the manufacture r’s recommendations and as shown in the plans. Include all applicable posts, post anchorage systems and foundations, anchors, support wire ropes, braking elements, and mesh panels. Section 253. Provide barrier panels made of interlocking nominal 7- to 12 -inch diameter openings backed by a finer mesh placed on the roadside of the fence to prevent smaller rock from mov ing past the barrier as shown in the plans.
(a)Equipment. List equipment to be used for roadside rockfall protection fence work. Include equipment capacities and intended uses.
(b)Design. Complete required design according to the manufacturer ’s recommendations for all component parts including, but not limited to , the layout of posts, post anchorage systems, post foundations, braking elements, anchors, and support ropes. Design a system that meet or exceeds the requirements shown in the plans, including system height, energy level classification, MEL, SEL, classification for residual height for MEL, and elongation at the MEL.
(c)Installation. Locate the barrier panel at the centerline offset shown in the plans. Prepare the alignment of the flexible rockfall barrier system by clearing debris that is accumulated in the roadside ditch. Dispose of the material according to Subsection 203.07 . Erect the post anchorage systems, anchors, and posts according to the approved drawings, the construction sequence, and the manufacturer’s recommendations. Install posts within the required manufacturer’s tolerances for alignment and orientation. Install and fasten top and bottom support wire ropes according to the manufacturer’s recommendations. Fasten wire ropes only after the tested anchors have been accepted in writing. Install and connect the rockfall mesh according to the manufacturer’s recommendations.
(d)Post anchorage systems. Locate, anchor, and install posts according to the manufacturer’s recommendations and the approved drawings. Do not exceed the manufacturer’s spacing recommendations for the posts, center to center. Perform excavation and foundation preparation work according to Section 209. Perform foundation work for the posts and anchors according to approved drawings, construction sequence, and the manufacturer’s recommendations. Foundations may be either precast or cast-in-place. If cast -in-place syste ms are used, do not disturb or apply any load to any of the post anchorage systems until the concrete has cured at least 5 days or as recommended by the manufacturer, whichever is greater.
(e)Anchors. Locate, orient, and install anchors according to the manuf acturer’s recommendations and approved drawings for support of system appurtenances. Include posts, top and bottom support wire ropes, and other elements as specified by the manufacturer.
(f)Anchor testing. Verify anchor capacities by conducting axial pullout proof tests on all the end post base anchors, lateral anchors for support and lateral ropes, and upslope anchors; and 25 percent of the intermediate post base anchors, as selected by the CO. Provide test loads as specified by the manufacturer. Proof tests will be accepted when an anchor maintains the test load for 10 minutes without loss of load. Conduct the test against a temporary yoke or load frame with no part of the yoke or load frame within 3 feet of the anchor. If more than two of the tested anchors fail, test all anchors. Replace failed anchors. Collect samples of the grout from two batches of grout that is being used for grouting and submit grout cubes to an independent testing firm for breaking strength testing. Provide 3- day and 7- day unconfined compression test results to the CO. The CO may also request samples for testing. Complete anchor testing before conducting additional work on the post anchorage systems or connecting any system components to any anchors.
(g)Wire ropes and m esh panels. Install and fasten support wire ropes according to the manufacturer’s recommendations. Install and connect the mesh panels and backing material according to the manufacturer’s recommendations.
(h)Manufacturer certification. Conduct an on- site review of the co mpleted flexible barrier systems with a manufacturer ’s representative. Provide written certification from the manufacturer to the CO for approval that the flexible rockfall barrier systems have been installed according to the manufacturer’s recommendations.
265.07Flexible Rockfall Barrier System Test Results and Reporting. Submit test results. Maintain daily records of installation work. Include the following:
(a)Drawings depicting the location of each anchor, wire rope anchor, and post anchorage anchor. Note anchor designation, date drilled, the general drilling conditions, materials encountered, the location of significant drilling changes (such as geologic contacts, voids, or open fractures), dates of grouting operations, total anchor length, grout mix, grout volume, average grout pressure, hole diameter, and installation comments. Submit as -built drawings according to Subsection 104.06(c) .
(b)Anchor proof test data forms. Include the anchor designation, date of testing operation, signature of testing operator or inspector, identification numbers of jacking equipment, and comments.
265.08Acceptance. See Table 265-1 for sampling, testing, and acceptance requirements. Design of flexible rockfall barrier sys tems will be evaluated under Subsection 106.02 . Material for flexible rockfall barrier systems will be evaluated under Subsections 106.02, 106.03, and 106.04. Construction of flexible rockfall barrier systems will be evaluated under Subsections 106.02 and 106.04. Gabion barriers will be evaluated under Section 253. Safety scaling will be evaluated under Section 262. Treating exposed steel surfaces, treating galvanized steel field cuts, and repairing damaged galvanizing will be evaluated under Section 563.
Measurement
265.09Measure the Section 265 pay items listed in the bid schedule according to Subsection 109.02 and the following as applicable: When measuring roadside rockfall protection fence by the linear foot, measure along the alignment of the support posts be tween the terminal end posts. When measuring roadside rockfall protection gabion barriers by the cubic yard, measure in the structure.
Payment
265.10The accepted quantities will be paid at the contract price per unit of measurement for the Section 265 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05 . Table 265-1 Sampling, Testing, and Acceptance Requirements
Material or
Product
(Subsection) Type of
Acceptance
(Subsection) Characteristic Category Test Methods
Specifications Sampling
Frequency Point of
Sampling Split
Sample Reporting
Time Remarks
Production
Non-shrink
grout (701.04(b)(2) ) Measured & tested for conformance (106.04 ) Flow – ASTM C939 1 per mix design
Source of
Material Yes, if
requested Within 24 hours after completion of test –
Compressive
strength (3 -day & 7-day) – ASTM C109 1 set from each batch of grout Source of
Material Yes, if
requested Within 24 hours after completion of test –
Proof test for
flexible rockfall barrier anchors Measured & tested for conformance (106.04 ) Deformation – Subsection
265.06(f) Subsection
265.06(f) Installation No Within 24 hours after completion of test –