Punching for steel plates shall be as follows: Bolt holes along those edges of the plates that will form longitudinal seams in the finished structure shall be staggered in rows 2 inches apart, with one row in the valley and one on the crest of the corrugation. Bolt holes along those edges of the plates that will form circumferential seams in the finished structure shall provide for a bolt spacing not more than 12 inches. The minimum distance from center of hole to edge of plate shall be not less than 14 times the diameter of the bolt. The diameter of the bolt holes in the longitudinal seams shall not exceed the diameter of the bolt by more than inch. Punching for aluminum plates shall be as follows: Bolt holes along those edges of the plates that will form longitudinal seams in the finished structure shall be on a double row with center to center dimension of 1-3/4". In all structures the longitudinal seam shall be comprised of two bolts in each valley and crest of each corrugation. The standard center to center dimensions of bolt holes that will form the circumferential seam in the finished structure shall be 9-5/8". The minimum distance from the center of hole to the edge of the plate shall not be less than 1-3 times the diameter of the bolt. Tolerance of all hole diameters and spacing shall be as indicated on the Drawings. 617.05 Footings for Arches. Footings for arches shall be constructed in accordance with the design shown on the plans and with the requirements prescribed in other sections for the several kinds of work involved. 617.06 Erection. Structural-plate pipe, pipe-arches, and arches shall be erected in their final position by connecting the plates with bolts at longitudinal and circumferential seams. Drift pins may be used to facilitate matching of holes. All plates shall be placed in the order recommended by the manufacturer with joints staggered so that not more than three plates come together at any one point. All bolts shall be drawn tight, without overstress, before beginning the backfill. Steel bolts for structural-plate sections shall be torqued during installation to a minimum of 100 ft.-lbs., and a maximum of 300 ft.-lbs. For power-driven tools, the hold-on period may vary from 2 to 5 seconds. The bolts for aluminum structural-plate sections shall be torqued during installation to a minimum of 100 ft. lbs. and a maximum of 200 ft. lbs. Bolts shall be of sufficient length to provide a full nut. After structural plate pipe, pipe arches or arches have been erected all spots where damage has occurred to spelter shall be given two coats of approved hot asphalt paint, or shall be wire brushed and given 2 coats of zinc dust-zinc oxide paint, as directed by the Engineer. Method of Measurement 617.07 Structural-plate pipe, pipe-arches, and arches will be measured in linear feet, installed in place, completed, and accepted. The number of linear feet will be measured along the invert center line for pipe and pipe arches, and the average of the springing line lengths for arches. Basis of Payment 617.08 The quantities, determined as provided above, will be paid for at the contract price per unit of measurement, respectively, for each of the particular pay items listed below that is shown in the bid schedule, which prices and payment will be full compensation for the work prescribed in this section, except excavation and backfill which will be paid for as prescribed in Sections 206 and 603, and footings for arches which will be paid for as prescribed in the applicable sections. Payment will be made under: 618.01 This work shall consist of cleaning and reconditioning existing pipe and appurtenant structures in reasonably close conformity with these specifications and as shown on the plans. Materials 618.02 Materials used for repair or replacement under the various pay items shall conform to the requirements of the applicable sections. Construction Requirements 618.03 Pipe Removed and Cleaned. The pipe shall be carefully removed and cleaned of foreign material, both within the barrel and at the jointed ends. 618.04 Pipe Cleaned in Place. All foreign material within the barrel shall be removed and disposed of by methods which do not damage the pipe. If approved by the Engineer, all or part of the pipe designated to be cleaned in place may be removed, cleaned, and relaid in accordance with the applicable sections. In such cases, the Contractor shall furnish all material required to replace damaged pipes and joints, perform all excavation and backfill, and re-lay the pipe, all at the contract bid price for this item. 618.05 Re-laying or Stockpiling Salvaged Pipe. Re-laying of pipe selected by the Engineer to be removed and cleaned shall be done where shown on the plans, in accordance with the appropriate section for the kind of pipe involved. The Contractor shall furnish all jointing material and shall replace pipe broken by him, in sufficient lengths to complete the designated length to be re-laid without added compensation. Salvaged pipe designated to be stockpiled shall be placed where shown on the plans and as directed by the Engineer. No pipe which has sustained structural damage shall be placed in stockpiles. The Contractor shall dispose of such damaged pipes at an approved location. 618.06 Reconditioning Drainage Structures. Structures such as manholes, inlets and the like, designated on the plans or directed by the Engineer to be reconditioned shall have all debris removed, leaks repaired, missing or broken metalwork replaced, and each structure left in operating condition. Method of Measurement 618.07 Measurement will be made of the number of linear feet of pipe acceptably cleaned, removed, re-laid or stockpiled as designated in the bid schedule, irrespective of the kind or size involved. Pipe removed, cleaned, and re-laid will be measured in final position. Pipe removed, cleaned, and stockpiled will be measured by totaling the nominal laying lengths of all pipe units acceptably removed, cleaned, and placed in the stockpile. Pipe cleaned in place will be measured along the flow line of pipe line acceptably cleaned as directed. Measurement of drainage structures reconditioned will be made by actual count of the total number of units of each type acceptably completed. Basis of Payment 618.08 The quantities determined as provided above will be paid for at the contract price per unit of measurement respectively, for each of the pay items below that appear in the bid schedule, which price and payment will be full compensation for the work of this section except excavation and backfill paid for under Section 206 in connection with re-laying salvaged pipe. Excavation and backfill necessary for pipe removal operations shall be done as part of the work of this section. The Contractor shall remove and replace without added compensation any pipe damaged by his operations and which cannot be acceptably repaired in place. Payment will be made under: Pay item Pay unit 618(1) Removing, cleaning, stockpiling salvaged culvert pipe... Linear foot. Linear foot. Linear foot. If no pay items from the list above appear in bid schedule, pipe removed will be considered as included in the work of Section 202. Section 619.-RIPRAP Description 619.01 This work shall consist of riprap for bank protection and erosion control furnished and constructed in accordance with these specifications and in reasonably close conformity with the lines, grades, and dimensions and at the locations shown on the plans or established by the Engineer. The types of riprap included in this specification are: (a) Dumped Riprap. Dumped riprap consists of stone or broken concrete dumped in place on a filter blanket or prepared slope to form a well-graded mass with a minimum of voids. (b) Wire-Enclosed Riprap. Wire-enclosed riprap consists of mats or baskets fabricated from wire mesh, filled with stone, connected together and anchored to the slope. (c) Grouted Riprap. Grouted riprap consists of riprap with all or part of the interstices filled with portland cement mortar. (d) Concrete Riprap in Bags. Concrete riprap in bags consists of concrete in cement sacks or suitable burlap bags. (e) Concrete-Slab Riprap. Concrete-slab riprap consists of concrete, plain or reinforced, poured in place or precast concrete blocks. (f) Filter Blanket. A filter blanket consists of one or more layers of graded material placed on the bank before placing the riprap in order to prevent the bank material from passing through the riprap protection. The thickness and gradation of filter blanket will be shown on the plans. MATERIALS 619.02 Materials. All materials shall meet the following requirements: (a) Dumped Riprap. Stone used for dumped riprap shall be hard, durable, angular in shape; resistant to weathering and to water action; and shall meet the gradation requirements for the class specified. Neither breadth nor thickness of a single stone should be less than onethird its length. Rounded stone or boulders will not be accepted unless authorized by special provisions. Broken concrete may be substituted for stone when authorized by special provisions. Shale and stone with shale seams are not acceptable. The minimum weight of the stone shall be 155 pounds per cubic foot as computed by multiplying the specific gravity (bulksaturated-surface-dry basis, AASHTO T 85) times 62.5 pounds per cubic foot. The acceptability of the stone will be determined by service records and/or by suitable tests. If testing is required, suitable samples of stone shall be taken in the presence of the Engineer at least 25 days in advance of the time when the placing of riprap is expected to begin. The approval of some stone from a particular quarry site shall not be construed as constituting the approval of all stone taken from that quarry. In the absence of service records, resistance to disintegration from the type of exposure to which the stone will be subjected will be determined by any or all of the following tests as stated in the special provisions: (1) When the riprap must withstand abrasive action from material transported by the stream, the abrasion test in the Los Angeles machine shall also be used. When the abrasion test in the Los Angeles machine (AASHTO T 96) is used, the stone shall have a percentage loss of not more than 40 after 500 revolutions. (2) In locations subject to freezing or where the stone is exposed to salt water, the sulfate soundness test (AASHTO T 104 for ledge rock using sodium sulfate) shall be used. Stones shall have a loss not exceeding 10 percent with the sulfate test after five cycles. (3) When the freezing and thawing test (AASHTO T 103 for ledge rock procedure A) is used as a guide to resistance to weathering, the stone should have a loss not exceeding 10 percent after 12 cycles of freezing and thawing. Stone shall be free from overburden, spoil, shale, and organic material and shall meet the following gradation requirements for the class specified: Each load of riprap shall be reasonably well graded from the smallest to the maximum size specified. Stones smaller than the specified 10 percent size and spalls will not be permitted in an amount exceeding 10 percent by weight of each load. Control of gradation will be by visual inspection. The contractor shall provide two samples of rock of at least 5 tons each, meeting the gradation for the class specified. The sample at the construction site may be a part of the finished riprap covering. The other sample shall be provided at the quarry. These samples shall be used as a frequent reference for judging the gradation of the riprap supplied. Any difference of opinion between the Engineer and the Contractor shall be resolved by dumping and checking the gradation of two random truck loads of stone. Mechanical equipment, a sorting site, and labor needed to assist in checking gradation shall be provided by the Contractor at no additional cost to the Government. (b) Wire-Enclosed Riprap. Stone used for wire-enclosed riprap shall meet the requirements of Section 619.02(a) except for size and gradation of stone. Stone used shall be well graded within the sizes available and 70 percent, by weight, shall exceed in least dimension the wire mesh opening. The maximum size of stone, measured normal to the slope, shall not exceed the mat thickness. Wire mesh shall be galvanized woven fencing conforming to the specifications for Fence Fabric, Subsection 710.02, and shall be of the gage and dimensions shown on the plans. Ties and lacing wire shall be No. 9 gage galvanized unless otherwise specified. (c) Grouted Riprap. Grout for grouted riprap shall consist of one part portland cement and three parts sand, thoroughly mixed with water to produce grout having a thick creamy consistency. The minimum amount of water should be used to prevent excess shrinkage of the grout after placement. The cement, sand, and mixing shall conform to the specifications in Subsection 705.05 The stones for grouted riprap shall meet the requirements of Section 619.02(a) except for size and gradation. Size and gradation will be specified for each particular project. Stone shall be free of fines which prevent penetration of grout and care shall be taken in placing the stone to keep earth or sand from filling the spaces between the stones. (d) Concrete Riprap in Bags. Concrete riprap in bags shall consist of class C concrete in cement sacks or suitable burlap bags. (e) Concrete-Slab Riprap. Concrete for concrete-slab riprap shall be class B unless the riprap is exposed to salt water, in which case it shall be class A. The slabs shall be of two types, plain concrete or reinforced. If reinforcement is specified, it shall be furnished as shown on the plans. Except as modified herein, materials and construction shall conform to Section 552. (f) Filter Blanket. The filter blanket shall consist of one or more layers of gravel, crushed rock, or sand of the thickness shown on the plans. The gradation of material in each layer of the filter blanket shall meet the requirements of the special provisions. All material comprising the filter blanket shall be composed of tough, durable particles, reasonably free from thin, flat, and elongated pieces, and shall contain no organic matter or soft, friable particles in quantities in excess of those approved by the engineer. Construction Requirements 619.03 General. Foundation trenches and other necessary excavations shall be excavated by the Contractor as provided in Section 206, and approved by the Engineer before the placing of riprap is begun. Slopes to be protected by riprap shall be free of brush, trees, stumps, and other objectionable material and be dressed to a smooth surface. All soft or spongy material shall be removed to the depth shown on the plans or as directed by the Engineer and replaced with approved material. Filled areas will be compacted as specified in Section 203. Protection for structure foundations shall be provided as early as the foundation construction permits. |