628.01 Description. This item consists of furnishing and placing
topsoil on completed slopes and ditches according t o these specifications and at locations shown on the plans or as directed by the Engineer.
628.02 Materials. Topsoil may be obtained from sources outside
the right-of-way limits or from areas within the pr oject limits that will be occupied by cuts and/or embankments. When topsoil is furnished from sources outside the right-of-way, th e Contractor shall be responsible for locating and obtaining the mater ial and for performing all work, including erosion control, pre vention of water pollution, and restoration, according to the specif ications. The cost of such work will be considered included in the con tract unit price bid for Topsoil Furnished and Placed. At the reque st of the Engineer, the Contractor shall furnish copies of ag reements with the property owners. Topsoil from all sources shall be the surface layer of soil with no admixture of refuse or any material toxic to plant growth and shall be reasonably free from subsoil and stumps, roots, brush, stone, clay lumps, or similar objects larger than 2" (50 mm) in greatest diameter. In no case shall topsoil be excavated mo re than 12" (300 mm) from the original ground level. Brush and other vegetation that will not be incorporated with the s oil during handling operations shall be cut and removed. Ordinary sods and herbaceous growth, such as grass and weeds, shall not be remov ed but shall be thoroughly broken up and intermixed with the soil d uring handling operations. Topsoil may contain a reasonable amoun t of waste from clearing operations, such as small twigs and roots, that can be expected to reach early decay.
628.03 Construction Operations. (a) Removing, Stori ng, and
Handling Topsoil. Topsoil stripped from within the project shall be moved to areas on the right-of-way, or other approv ed locations, and stockpiled. When measurement is to be by the cross section method, 508 the stockpiles shall be uniformly shaped and suscep tible to ready measurement by the cross section method. Stockpile s shall be located so that they will not interfere with any pr oposed construction nor constitute drainage, traffic, or other hazards, either to the project, the general public, or adjacent property. Storage should be in such locations that will afford easy access for loading, hauling, and replacement. The stored topsoil shall be protected from contamination. If the condition of the soil is unsuitable due to e xcessive moisture, frost, or other conditions, the Contracto r shall cease work under this item until the soil is in a suitable con dition. Topsoil stripped from within the project limits sha ll be removed prior to the taking of original cross sections. Th e Contractor shall schedule the work in coordination with the Resident Engineer so as to minimize any delay between the stripping of the topsoil, the taking of original cross sections, and the beginnin g of excavation and/or embankment construction. Failure of the Con tractor to properly schedule the work will not be considered a s grounds for extension of time nor for additional payment due to any resulting delays.
b.Placing Topsoil. Topsoil shall be distributed over the completed slopes and ditches to a depth as shown on the plans or designated by the Engineer. Spreading and dressing of the topsoil layer shall be uniform insofar as possible. After spreading, any remaining large roots, branches, or other foreign s ubstances shall be removed to leave a smooth and clean appearance. Light rolling, disking, or other type manipulation, including sprinkling, shall be applied as necessary to cause the newly spread layer to pulverize, mix, and adhere to the slopes. Topsoil shall be placed on areas that are to receive seed or sod mul ch as soon as practicable after the earthwork is completed, but s hall not be placed until after final cross sections are taken. The Co ntractor shall schedule the work in coordination with the Resident Engineer so as to minimize any delay between the completion of the earthwork, the taking of final cross sections, and the placement o f topsoil. Failure of the Contractor to properly schedule the work wil l not be considered as grounds for extension of time nor for additional payment due to any resulting delays. 509 (c) Restoration. Additional work and materials required because of loss through erosion will be paid for under the appropriate contract item. Additional work and materials requi red due to the Contractor's negligence in maintaining the complete d work, including failure to apply and maintain seeding, mu lch cover, sod mulch, and/or solid sod as required, shall be accom plished at no cost to the Department. The storage sites for topsoil within the right-of-w ay shall be dressed to conform to the adjacent area after the s torage piles have been removed. If the Contractor elects to obtain topsoil from are as within the project limits that are to be occupied by embankmen ts, additional borrow material required to replace the topsoil wil l be measured and paid for under the appropriate item.
628.04 Method of Measurement. Topsoil furnished from
outside the right-of-way will be measured by the cu bic yard (cubic meter) in vehicles at the point of delivery for use on the project. Topsoil obtained from within the project limits wil l be measured by the cubic yard (cubic meter) either in stockpiles b y the cross section method or in vehicles at the point of delivery for spreading. No adjustment will be made for swell.
628.05 Basis of Payment. Work completed and accepted and
measured as provided above will be paid for at the contract unit price bid per cubic yard (cubic meter) for Topsoil Furnished and Placed, which price shall be full compensation for furnishing, hauling, stockpiling, moving, and placing topsoil; and for all labor, equipment, tools, and incidentals necessary to comp lete the work. Payment will be made under: Pay Item Pay Unit Topsoil Furnished and Placed Cubic Yard (Cubic Mete r) 510 SECTION 629 GABIONS
629.01 Description. This item shall consist of the construction
of interconnected rectangular wire-mesh baskets fil led with coarse nondegradable stone to be used as retaining walls a ccording to these specifications and conforming to the lines, grades, dimensions, locations, and design shown on the plans, or as dir ected.
629.02 Materials. (a) All wire for gabion baskets shall meet the
requirements of Subsection 106.01. Wire for gabion baskets shall be 11 gage (3.0 mm), or equivalent, with a tensile str ength between 60,000 to 85,000 psi (415 and 585 MPa). The minimu m zinc coating of the wire shall be 0.80 oz./sq. ft (245 g /sq m) of uncoated wire surface complying with AASHTO T 65. Lacing wi re shall comply with the same specifications as wire used in the mesh and shall be 13½ gage (2.2 mm). All perimeter edges (m esh edge and selvage rod wires) of the mesh forming the gabion s hall be securely selvaged with wire of 9 gage (3.8 mm) or greater. The wire mesh shall be fabricated in such a manner as to be nonra veling as defined by the ability to resist pulling apart at any of th e twists or connections forming the mesh when a single wire in a section of mesh is cut. Openings of the mesh shall be approxi mately 4½" (115 mm) in the longest dimension by approximately 3¼" (80 mm).
b.Gabion baskets shall be supplied as specified on th e plans. Gabions shall be fabricated in such a manner that t he sides, ends, lid, and diaphragms can be assembled at the construction site into a rectangular basket of the required size. Gabions a re to be of single unit construction with the base, ends, and sides ei ther woven into a single unit or one edge of these members connected to the base section of the gabion in such a manner that strengt h and flexibility at the point of connection are at least equal to that of the mesh.
c.Stone for filling gabion baskets shall be obtained from an approved source and shall consist of sandstone, lim estone, or other hard and durable stone that will be resistant to th e action of air and water. The stone shall consist of field stone or r ough unhewn quarry stone, angular, and with fractured faces. The ston e shall weigh not less than 150 pounds per solid cubic foot (2400 kg per solid cu m) with a percent of wear not greater than 45 by the L os Angeles Test (AASHTO T 96). Based on any one hauling unit shipm ent or 511 delivery, the maximum piece size shall be not great er than 8" (200 mm) in any dimension. The minimum stone size shall be 4" (100 mm) except for dirt and fines accumulated from quarrying or loading operations, which shall not exceed 5%.
629.03 Construction Requirements. (a) Excavation. The
existing material shall be excavated to the require d depth. Soft and yielding material shall be removed and replaced wit h suitable material and the entire subgrade shall be thoroughl y compacted.
b.Backfilling. The area under the gabion walls shall be backfilled with granular material and thoroughly co mpacted.
c.Gabion Baskets. Each gabion unit shall be assembled by binding together all vertical edges with wire ties on approximately 6" (150 mm) spacing or by a continuous piece of con necting wire stitched around the vertical edges with a coil spac ing of 5" (125 mm). Empty gabion units shall be set to line and grade as shown on the plans or as directed by the Engineer. Gabion baskets shall be securely fastened to all adjacent gabion b askets to the satisfaction of the Engineer. It is not intended t hat the fastenings to adjacent gabions equal the strength of the baskets themselves. A standard fence stretcher, chain fall, or iron rod m ay be used to stretch the wire baskets and hold alignment. The gabion baskets shall be filled with stone caref ully placed by hand or machine to assure alignment and avoid bulge s with a minimum of voids. After a gabion basket has been f illed, the lid shall be bent over until it meets the sides and edg es. The lid shall then be secured to the sides, ends, and diaphragms with wire ties or connecting wire in the manner described above.
d.Filter Fabric. A filter fabric is to be placed on top and back of filled gabion baskets as shown on the plans.
e.Backfill. The area behind gabion walls is to be backfilled with embankment material as approved by the Enginee r. Care shall be taken so as not to damage filter fabric when pla cing backfill.
629.04 Method of Measurement. Gabions will be measured by
the cubic yard (cubic meter) of gabion baskets in p lace using the specified dimensions.
629.05 Basis of Payment. Work completed and accepted under
this item and measured as provided above will be pa id for at the 512 contract unit price bid per cubic yard (cubic meter ) for Gabions, which price shall be full compensation for furnishi ng materials; for assembling and securing baskets; for placing stone in baskets; and for all equipment, tools, and incidentals necessary to complete the work. Excavation, material for backfill, and filte r fabric will be paid for under other appropriate contract items. Payment will be made under: Pay Item Pay Unit Gabions Cubic Yard (Cubic Meter)
Source: , Edition.