304 STRUCTURAL PLATE PIPE AND STRUCTURAL PLATE PIPE ARCH CULVERTS
From MDOT Policy Manual
- Furnish and install structural plate pipe and structural plate pipe arch culverts.
No. 57 Aggregate 901.01 Crusher Run Aggregate CR-6 901.01 Portland Cement Concrete 902.10, Mix No. 2 Curing Compound 902.07.03 Structural Plate for Pipe and Pipe Arches 905 Detectable Utility Marking Tape Contract DocumentsThe written agreement executed between an Administration and the successful bidder, covering the performance of the work and furnishing of labor, equipment and materials, by which the Contractor is bound to perform the work and furnish the labor, equipment and materials, and by which the Administration is obligated to compensate him therefore at the mutually established and accepted rate or price. The Contract Documents shall include the Invitation for Bids, Notice to Contractors, Instructions to Bidders, Proposal, Contract Forms and Bonds, General Provisions, Specifications, Supplemental Specifications, all Special Provisions, all Technical Provisions, all Plans and Notices to Proceed, also any written Change Orders and Supplemental Agreements that are required to complete the construction of the work in an acceptable manner, including authorized extension thereof
- 304.03.01 Fabrication. Submit working drawings, including erection diagrams and strutting tables, for approval. Include proposed lengths and lifting locations of preassembled sections in the erection diagrams. Upon approval, shop fabricate the plates, including all required holes, to the required dimensions. Ship the plates complete, with proper markings and all necessary connection devices.
- Ensure the plate configurations have radii and curvature according to AASHTOAmerican Association of State Highway and Transportation Officials Load and Resistance Factor Design (LRFD) BridgeA structure including supports erected over a depression or an obstruction, such as water, highway, or railway, and having a track or passageway for carrying traffic or other moving loads, and having an opening measured along the center of the roadway of more than 20 feet between undercopings of abutments or spring lines of arches, or extreme ends of openings for multiple boxes; it may also include multiple pipes, where the clear distance between openings is less than half of the smaller contiguous opening. For lengths, all dimensions shall be parallel to the center line of the roadway. The dimensions of handrails will not be taken into account in measuring bridge lengths. Any bridge or highway grade separation structure includes the connecting highways, substructure, superstructure, roadway approaches, entrance plazas, interchanges, overpasses, underpasses, and other structures which the Administration may deem necessary together with all property rights, easements, franchises, and interests acquired by the Administration for the construction and operation of the bridge. Design Specifications. When bottom plates of circular pipes are specified to the thicker than top and side plates, cover at least 25 percent of the periphery of the circle with the thicker plate. For pipe arches, the thicker plates include corner plates as well as bottom plates. Lay these culverts on a firm bed, true to the specified line and grade.
- Along those edges of the plates that will form longitudinal seams in the finished structure, stagger bolt holes in rows 2 in. apart, with one row in the valley and one in the crest of the corrugations unless otherwise specified. Along those edges of the plates that will form circumferential seams in the finished structure, provide a bolt spacing of not more than 12 in. Ensure the diameter of the bolt holes in the longitudinal seams do not exceed the diameter of the bolt by more than 1/8 in.
- Shop cut all edges to line and grade, and keep them free from oxide and burrs. Stagger connections so that no more than three plates come together at any one point. Form plates to provide lap joints.
- 304.03.02 Excavation. When a structural plate pipe or structural plate pipe arch is to be laid on existing ground, on or under fill, construct embankment to a height of at least 18 in., but not more than 3 ft above the proposed top of the pipe. Then excavate the trench to a width of twice the outside diameter of the pipe or the outside diameter plus 18 in. on each side, whichever is less. Handle excavated material according to 402.03.01.
- 304.03.03 Foundation Preparation. Provide bedding according to 303.03.01 (c). Set rails and then screed the foundation to the exact shape of the bottom plates immediately prior to erection.
- 304.03.04 Erection. When strutting is required, ensure it is uniform from end to end. Keep struts in place until backfilling is complete. Tighten nuts and bolts to between 100 and 200 ft·lb of torque.
- When washers are specified, place them under the turned element. Distribute bolts over the section being assembled. Align holes by shifting the plates. For bottom plates, place the nuts inside the structure. Do not draw the nuts tight until the section is assembled. Before placing backfill, tighten all nuts and test to ensure it meets specified torque requirements.
- 304.03.05 Backfill.
- The presence of large lumps, clods, frozen material, or rocks in the backfill are unacceptable.
- Place backfill material along the side of the pipe for the full width of the trench in layers not exceeding an uncompacted depth of 6 in. Compact each layer simultaneously on both sides of the pipe using an approved mechanical tamper and according to Section 210. Compact the backfill thoroughly under the haunches of the pipe.
- Continue this method of filling and compacting until the compacted backfill material is at least 18 in. above the top of the structure. For structures without headwalls, begin placing backfill at the center of the structure. If the structure includes headwalls or spandrel walls, begin placing backfill at one wall and work toward the opposite side. When batteries or multi-barrel installations are specified, elevate backfill between cells equally on each side of each pipe or pipe arch.
- Protect pipes from damage due to construction activities. Do not drive equipment within 4 ft when measured horizontally from the pipe nor drive equipment over the pipe until at least 24 in. of compacted fill is over the pipe.
- Place detectable utility marking tape in the trench immediately above the structural backfill. Demark the tape as to its purpose, i.e., "STORM DRAIN".
- Inspection and Acceptance. Within 30 days following installation, and in the presence of the EngineerAny person designated by the Administrator or the procurement officer, acting directly or through his duly authorized representative, such representative acting within the scope of the particular duties assigned to him or of the authority given him., visually inspect all pipe culverts. Any cracks, differential movement, efflorescence, rust stains, spalls, exposed reinforcement, slabbing, dents, buckling, holes, damaged coating, obstructions, improperly engaged joints, improper gasket placement, excessive joint gaps, misaligned joints, excessive deflection, or undue horizontal or vertical misalignment will be cause for repair or replacement. Video inspect pipe which cannot be physically accessed for inspection. Ensure that thermoplastic pipe deflection does not exceed 5 percent
- 304.03.06 Concrete Invert. When specified, pave the pipe or arch pipe invert using Concrete Mix No. 2. Place and cure the concrete according to Section 420.
- 304.03.07 End Treatment. Shop fabricate the ends of structural plate pipes and structural plate pipe arches on a bevel to fit and be flush with the slope and alignment of the surface through which they protrude, except that where an end wall or masonry slope protection is specified, shop fabricate the ends to fit that construction. Ensure the ends of all structural plate pipes and structural plate pipe arches that require an end treatment (end wall or slope protection) contain hook bolts for anchorage into the concrete.
- Furnish and install headwalls for structural plate pipes and pipe arches according to Section 305. Unless otherwise specified, constructed these structures parallel to the proposed outer edge of the roadway shoulder.
304.04 MEASUREMENT AND PAYMENT.
- The payment will be full compensation for all applicable fabrication, assembly, excavation, sheeting, shoring, strutting, dewatering, hauling, invert paving, storing, rehandling of material, removal and disposal of excess and unsuitable material, tamped fill, foundation preparation, backfill, bedding, compaction and for all material, labor, equipment, tools, and incidentals necessary to complete the work.
- 304.04.01 Structural Plate Pipe and Structural Plate Pipe Arch Culverts will be measured and paid for at the Contract unit price per linear foot. The basis of measurement and payment will be as follows: measure the top length and the bottom length and average. The average length will be the pay length for each pipe in the structure. For multiple pipes, the length will be totaled to obtain the total pay length.
- 304.04.02 Excavation required below the planned elevation will be measured and paid for as specified in 301.04.
- 304.04.03 Selected backfill will be measured and paid for according to 302.04.
- 304.04.03 Headwalls will be measured and paid for according to 305.04.