440 Page 307440 STRUCTURAL PLATE PIPE AND STRUCTURAL PLATE PIPE ARCH CULVERTS
440.1DESCRIPTION
This work consists of furnishing and installing structural plate pipe and structural plate pipe arches.
440.2MATERIALS
Structural plate pipe and pipe arches will conform to Section 990.
440.3CONSTRUCTION REQUIREMENTS
A.Fabrication: Plates will have a 2 inch lip beyond each end crest therefore the actual length of a given structure will be approximately 4 inches longer than the nominal length, except when skewed or beveled. Plates at longitudinal and circumferential seams will be connected by bolts. Joints will be staggered so no more than three plates come together at any point. B.Erection: Pipe and pipe arches will be assembled according to the manufacturer's assembly instructions. Bolts will not be torqued above 300 foot-pounds C.Installation: Trenches will be excavated to a width that allows for thorough compaction of the bedding and backfill material under and around the pipe. Where feasible, trench walls will be vertical. The trench bottom will be firmly compacted for its full length and width. The foundation for the bedding will provide a uniform stable support. Removal of unstable material or rock below the bedding grade will be performed as set forth in Section 421. The bedding will consist of an earth or gravel cradle of uniform density, shaped to fit the lower part of the pipe for at least 10% of its overall height. D.Backfill Above Bedding Grade: Material used for backfill will be embankment material encountered on the project free of organic material and rock or will be as specified in the plans. Moisture and density requirements for backfill will meet the requirements of Section 120 or as specified in the plans. The backfill material will be pre-moistened if necessary to obtain uniform moisture. Selected embankment material will be placed along the pipe in layers not exceeding 6 inches loose depth and thoroughly compacted by mechanical compactors to the specified density before the successive layers are placed. The width of the berms on each side of the pipe will be twice as wide as the external diameter of the pipe or 12 feet, whichever is less. This method of backfilling will be continued until the embankment is at least 2 feet over the top of the pipe. 440 Page 308In trench installations, the backfill width will be equal to trench width. The backfill will be brought up evenly on both sides of the pipe for its full length. This method of backfilling will be continued until the embankment is at least 2 feet over the top of the pipe. E.Workmanship: The completed structure will show careful, finished workmanship in all particulars. Among others, the following defects are specified as constituting poor workmanship: 1.Uneven laps. 2.Elliptical shaping on horizontal axis (unless specified). 3.Variation from a straight centerline. 4.Ragged edges. 5.Loose, unevenly lined or spaced bolts. 6.Illegible brand. 7.Bruised, scaled, or broken coating. 8.Dents or bends in the metal itself. The presence of one or more defect in any individual culvert plate or in any shipment will constitute sufficient cause for rejection.
440.4METHOD OF MEASUREMENT
Structural plate pipe and pipe arches will be measured to the nearest foot. Measurement of length will be made as follows: A.Vertical End Pipe: Pipe and pipe arches with vertical ends will be measured parallel to the centerline of the structure, from end to end of metal, exclusive of the 2 inch lip beyond the crest at each end. B.Beveled End Pipe: Pipe and pipe arches with beveled ends will be measured parallel to the centerline of the structure as the average of the end to end lengths of metal at the top and bottom exclusive of the 2 inches lip beyond the crest at each end.
440.5BASIS OF PAYMENT
The accepted quantities will be paid for at the contract unit price per foot complete in place. Payment will be full compensation for necessary steel and hardware, bedding operations, cost of selecting and placing backfill, furnishing and installing required granular or other bedding materials, and necessary excavation required. Authorized excavation of material below pipe foundation will be paid for as specified in Section 421.5 . 450 Page 309450 PIPE CULVERTS
450.1DESCRIPTION
This work consists of furnishing and installing polyethylene pipe, concrete and metal pipe, storm drains, and cattle passes excluding structural plate pipe and structural plate pipe arch culverts.
450.2MATERIALS
Materials will conform to the following Sections: A.Reinforced Concrete Pipe (RCP): Section 990. B.Corrugated Metal Pipe: Section 990. C.Corrugated Polyethylene Pipe: Section 990. D.High Density Polyethylene Pipe: Section 990. E.Flexible Watertight Gaskets: Section 990. F.Drainage Fabric: Section 831, Type A.
450.3CONSTRUCTION REQUIREMENTS
A.Reinforced Concrete Pipe (RCP) Culvert: All RCP sections, except pipe located between drop inlets, manholes, and junction boxes, will be tied with tie bolts as shown in the plans. All RCP sections only entering or exiting drop inlets, manholes, and junction boxes will be tied with tie bolts. The maximum allowable gap at any point between two sections of RCP will be 1 inch. The tie bolts will only be used to hold the completed RCP sections together and will not be used for pulling the RCP sections together. Lift holes will be covered or plugged to the satisfaction of the Engineer to prevent backfill from entering the pipe. When flexible watertight gaskets are used, the Contractor will install the flexible watertight gaskets in accordance with the manufacturer’s instructions. Unless otherwise specified in the plans, the RCP may be either tongue and groove or bell and spigot style RCP meeting the following requirements for each type of RCP allowed. 1.Tongue and Groove Style RCP: Tongue and groove style RCP culverts will be laid with the groove end of the pipe upstream and inserting the tongue end into the groove. Except where flexible watertight gaskets are specified, each joint will be effectively protected against infiltration of backfill soil by using a flexible watertight gasket conforming to Section 990, by filling the joint space with a sealant conforming to ASTM C990, or by providing a circumferential wrap on the exposed portion of the pipe joint above the cradle with a 1 foot wide strip of drainage fabric around the perimeter of the pipe. The drainage fabric will be centered over the joint. If the Contractors method of installation doesn’t secure the drainage fabric over the center of the joint while placing backfill, the Contractor