00450.40 389 Section 00450 - Structural Plate Shaped Structures Description
00450.00 Scope - This Work consists of constructing Structural Plate Pipe, pipe arches, plate
arches, horizontal ellipses, vehicular underpasses and special shaped Structure s.
00450.01 Definitions :
Structural Plate Pipe - Built-up pipe with a circular Cross Section of the type, thickness and diameter specified. It is fabricated with the vertical diameter about 5 percent greater than the nominal diameter as shown. Structural Plate Pipe Arch - Built-up pipe with a Cross Section made up of a multi -centered shape of four circular arcs, tangent to each other at their junctions, symmetrical about the vertical axis, and of the type, thickness and span specified. The size is designated by span and rise, measured from the inside crests of corrugations. Structural Plate Arch - Single or multiple radius Structure s comprised of a number of curved metal plates that form an arch shape when assembled. The Structure is designed to be supported along its lower edges on separately cons tructed reinforced concrete foundations, and of the design, type, thickness and span as shown. This size is designated by span and rise measured from the inside crests of corrugations. Structural Plate Horizontal Ellipse - Built-up pipe in an elliptical shape with the horizontal diameter approximately 20 percent greater than the nominal diameter. The size is designated by span and rise, measured from the inside crests of corrugations. Structural Plate Vehicular Underpass - Built-up pipe in a high arch s hape with large radius sides and invert, and small radius corners between sides and invert. The size is designated by span and rise, measured from the inside crests of corrugations. Materials
00450.10 Materials - Furnish Material s meeting the followin g requirements:
Aluminum Alloy Structural Plates .......................................................... 02430.20 Bolts, Nuts, and Washers ...................................................................... 02430.90 Commercial Grade Concrete ...................................................................... 00440 Galvanized Structural Plates ................................................................. 02430.10 Reinforcement ............................................................................................ 00530 Construction
00450.40 Trench Work - Excavate trench, prepare bedding, backfill and dispose of excavated
material according to Section 00510 and the following:
a.Trenches In Unstable Areas - Excavate unstable materials under the pipe or pipe arch and to a width of at least one- half the diameter or span width on each side of the Structure , to depths below the established elevation for the bases or foundation of the Structure , as directed. Unless otherwise directed, backfill with granular structure backfill. Bring the backfill Material to the moisture content requ ired for compaction and place in 6 inch layers. Compact each layer according to
00330.43 Bring the backfill Material to the elevation established.
00450.41 390 (b) Trenches in Unyielding Material - When Rock , hardpan or other unyielding material is encountered, re move it below the designated grade, as ordered, to a depth under the pipe or pipe arch equal to at least 1/2 inch per foot of fill height over the top of the pipe, but not less than 8 inches, nor more than three -fourths the vertical dimension of the Struct ure. Unless otherwise directed, backfill with granular structure backfill.
00450.41 Installation in Paved Areas - If Structure s are installed within paved areas to be
preserved, resurface according to Section 00495.
00450.42 Erection :
a.General - Assemble corrugated metal plates at the site of installation to the lines and grades shown or directed. Connect the plates at longitudinal and circumferential seams with bolts. Stagger joints so that no more than three plates come together at any one point. Each plate shall be curved to one or more circular arcs as required, and according to 02430.10, to provide an assembled Structure of specified dimensions and design. Retain any C amber specified for the invert when assembling and erecti ng the Structure s. Do not create an adverse grade in the Structure .
b.Plate Thickness - The thickness of the respective top, corner and bottom plates in any one Structure shall be as shown.
c.Bolts - Use at least 4 bolts per foot of longitudinal seam. Space bolts and bolt holes according to AASHTO M 167. Use additional bolts for special conditions of installation if called for in the Special Provisions or by the Plans . Unless otherwise allowed, place all bolts with nuts on the inside of the Structure .
d.Assembly - Assemble structural plate Structure s according to the manufacturer's assembly instructions and the following: • Hold the unsupported edges of all plates in position by temporary props . • Extend each row of side plates far enough to support the plate above until the first complete ring has been assembled. • Progressively install enough bolts to hold the plates in position. Do not tighten bolts until tightening will not interfere with adjus ting and matching of additional plates and sections. • Do not damage the galvanizing or other protective coating when using drift pins or pry bars. Repair any damage at no additional cost to the Agency. • After all plates are in place, progressively and uniformly tighten the bolts from one end of the Structure to the other end of the Structure . • Tighten bolts to at least 100 foot -pounds of torque for plates 0.188-inch thick or less, and 150 foot pounds of torque for plates more than 0.188 inch thick. • Recheck and retighten as necessary before backfilling. • Do not torque bolts above 300 foot -pounds during tightening.
e.Damaged Coating - Repair damaged galvanizing according to 02420.10(d).
00450.44 Arch Substructures and Headwalls - Rest each side of each arc h in a groove formed in
the concrete, or rest on a galvanized angle or channel securely anchored to or embedded in the Substructure. If the span of the arch is greater than 15 feet or the skew angle is more than 20 degrees, provide a metal bearing surface having a width at least equal to the depth of the corrugation. 00450.49 391 Metal bearings may be either rolled, structural, or cold-formed galvanized angles or channels, and shall be at least 3/16 inch thick. Anchor the horizontal leg securely to the Substructure on 24-inch centers or less. When the metal bearing is not embedded in a groove in the Substructure , punch one vertical leg and bolt to the bottom row of plates.
00450.45 Strutting - If strutting is required, place and remove according to 00445.44.
00450.46 Backfilling - Backfill and compact the trench according to 00510.48(d) and the following:
a.General - Perform backfilling so that a vertical elongation between 4 and 6 percent greater than the indicated normal diameter is maintained. Place backfill Material evenly on both sides of the Structure at least up to the three-quarter point of the Structure . Fill above the top of the pipe with minimum cover as indicated on the fill height table included with the Plans .
b.Exposed Pipe - Place and compact embankment Material s at exposed pipes according to Section 00445.
c.Tell- Tales - Install and remove tell -tales according to Section 00445.
d.Arches And Horizontal Ellipses - In addition to the other provisions of this Subsection, exercise care as follows:
1.Before Headwalls Are Placed - If backfilling pipes before headwalls are built, place the first backfill Material midway between the ends, forming as narrow a ramp as possible until the top of the pipe is reached. Build the ramp evenly from both sides, and compact the backfill Material as it is placed. After the ramps have been built to the top on each side of the pipe, deposit the remainder of the backfill evenly on both sides from the top of the pipe both ways f rom the center to the ends.
2.After Headwalls Are Placed - If headwalls are built before the pipe is backfilled, place the first backfill M aterial adjacent to one headwall until the top of the pipe is reached. Then deposit backfill Material evenly on both sides from the top of the pipe toward the other headwall. In multiple installations, follow the above procedures. Use care to place and bring the backfill up evenly on each side of each pipe to avoid unequal pressure. Compact the backfill Material thoroughly, but not excessively. Using water to hydraulically consolidate the backfill by ponding or jetting the backfill Material is not allowed.
00450.47 Footings and Headwalls - Construct footings and headwalls for arches according to the
design shown and the requirements of Sections 00440 and 00530.
00450.48 Contact Surfaces, Aluminum to Concrete - Where uncoated aluminum pipe will be in
contact with portland cement concrete, give the contact surfaces of the aluminum pipe a coating of asphalt mas tic according to 00445.47.
00450.49 Work Quality - The following defects constitute poor Work and the presence of any in an
individual culvert plate or in a shipment will be cause for rejection: • Dents or bends in the metal itself • Illegible brand • Loose or unevenly lined or spaced bolts • Ragged edges • Unrepaired, bruised, scaled or broken spelter coating 00450.80 392 • Uneven laps • Variation from the specified alignment • Wrong plate location Measurement
00450.80 Measurement - The quantities of Structural Plate Pipes, pipe arches, arches, horizontal
ellipses, and vehicular underpasses will be measured on the length basis, excluding overlaps and the lip of plates at Structure ends. Pipe arches and arches will be measured along the bottom centerline of the Structure s. The length of Structural Plate Pipes, horizontal ellipses, and vehicular underpasses will be the av erage of the top and bottom centerline measurements. Concrete for footings and headwalls will be measured on the volume basis, and will be the volume within the Neat Lines of the Structure as shown or directed. Excavation and backfill for pipes greater t han 72 inches in diameter will be measured according to Section 00510. Trench resurfacing will be measured according to 00495.80. Reinforcement for footings and headwalls will be measured on the weight basis according to 00530.80. Payment
00450.90 Payment - The accepted quantities of Work performed under this Section will be paid for
at the Contract unit price, per unit of measurement, for the following items: Pay Item Unit of Measurement
a.____ Inch Structural Plate Pipe ............................................................. Foot
b.____ Inch x ____ Inch Structural Plate Pipe Arch ................................. Foot
c.____ Inch x ____ Inch Structural Plate Arch ......................................... Foot
d.____ Inch x ____ Inch Structural Plate Ellipse ...................................... Foot
e.____ Inch x ____ Inch Structural Plate Vehicular Underpass ............... Foot
f.Structural Plate Concrete Footings and Headwalls .......................... Cubic Yard In item (a), the nominal size diameter of the pipe will be inserted in the blank. In items (b), (c), (d) and (e), the size of the span and rise of the Structure s will be inserted in the applicable blanks. Payme nt will be payment in full for furnishing and placing all Material s, and for furnishing all Equipment , labor, and Incidental s necessary to complete the Work as specified. Excavation and backfill for pipes greater than 72 inches in diameter will be paid for according to Section 00510. Trench resurfacing will be paid for according to 00495.90. Reinforcement for footings and headwalls will be paid for according to 00530.90. No separate or additional payment will be made for trench excavation, bedding, pipe zone Material, or trench backfill for pipes 72 inches and less in diameter. 00460.90
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Source: Oregon Standard Specifications for Construction, 2024 Edition. Pages 455–458 of 1,268. View official source ↗