502STRUCTURAL PLATE PIPE, PIPE- ARCHES, AND ARCHES

540 When an embankment is constructed prior to the digging of a trench and the installation of a pipe, payment for the construction of the embankment will be made under the appropriate item, such as Roadway Excavation or Borrow. Removal of rock, hard pan, other unyielding material, or soft, spongy , or other unstable material from the trench within the embankment will not be considered for payment. The repairing of the damage to existing pipe ends to which new pipe is to be joined and which cannot be seen in order to be assessed and the removal of any portion of a damaged existing pipe, as specified under Subsection 501- 3.03(B) of the specifications will be paid for in accordance with the provisions of Subsection 104.02 of the specifications. No measurement or direct payment will be made for furnishing and placing filter material, plating material, fittings, collars, bands, and the joining of new and existing pipes. For cast -in-place pipe, no separate measurement or payment will be made for the excavation or preparation of the trench; for furnishing, placing , and compacting backfill material; for pipe repair, when authorized by the Engineer; or for quality control activities; the cost being considered as included in the unit price per foot of pipe. For thermoplastic pipe and steel reinforced thermoplastic pipe, no separate measurement or payment will be made for post installation inspection, the cost being considered as included in the unit price per foot of pipe. End sections, measured as provided above, will be paid for at the contract unit price complete in place. ARCHES : 502- 1 Description: The work under this section shall consist of furnishing and erecting structural plate pipe, pipe -arches, and arches of the sizes, thicknesses, and dimensions shown on the project plans. They shall be installed at the locations specified on the project plans or as directed by the Engineer in reasonably close conformity to the lines and grades shown on the project plans or as established by the Engineer and the requirements of these specifications. 502- 2 Materials: Materials shall conform to the requirements of Section 1010 of the specifications, unless otherwise specified. TABLE OF CONTENTS INDEX 541 Plates shall be fabricated in accordance with the requirements of either AASHTO M 167, AASHTO M 219 or Federal Specification WW -P-405. Concrete shall conform to the requirements of Section 1006 of the specifications for the class and strength shown on the project plans. Reinforcing steel shall conform to the requirements of Section 1003 of the specifications. 502- 3 Construction Requirements: Excavating bedding and backfilli ng for the structural plate pipe, pipe- arches, and arches shall be performed as specified under Section 501 of the specifications and as specified herein and on the project plans. Excavating and backfilling for the concrete footings shall be performed as specified under Subsection 203- 5 of the specifications. Placement of reinforcing steel and structural concrete shall conform to the requirements of Sections 605 and 601 of the specifications, respectively. When backfill material is placed around and over arches before headwalls are in place, the material shall first be placed midway between the ends of the arch, forming as narrow a ramp as possible, until the top of the arch is reached. The ramp shall be constructed evenly from both sides and the material shall be compacted as it is placed. After the two ramps have been constructed to the top of the arch, the remainder of the material shall be placed from the top of the arch both ways from the center to the ends and as evenly as possible on both sides of the arch. When the headwalls are constructed before any backfill material is placed around and over the arch, the material shall first be placed adjacent to one headwall until the top of the arch is reached after which it shall be dumped from the top of th e arch toward the other headwall and as evenly as possible on both sides of the arch. In multiple installations, extreme care shall be taken so that the backfill material is brought up evenly on each side of each arch so that unequal pressures will be avoi ded. Plates shall be formed to provide lap joints with the upstream plate lapping over the downstream plate. The bolt holes shall be so punched that all plates having like dimensions, curvature, and the same number of bolts per foot of seam shall be inter changeable. Each plate shall be curved to the proper radius so that the cross- sectional dimensions of the finished structure will be as indicated on the project plans. Plates for forming skewed or sloped ends shall be cut to give the angle of skew or slope specified. Burned edges shall be free from oxide and burrs and shall present a workmanlike finish. Legible identification numerals shall be placed on each plate to designate its proper position in the finished structure. TABLE OF CONTENTS INDEX 542 Steel plates shall be punched so that bolt holes along those edges of the plates that will form longitudinal seams in the finished structure will 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 of not more than 12 inches. The minimum distance from center of hole to edge of plate shall be not less than 1.75 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 1/8 inch. Aluminum plates shall be punched so that bolt holes along those edges of the plates that will form longitudinal seams in the finished structure will be on a double row with a center -to-center dimension of 1- 3/4 inches. 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 inches. The minimum distance from the center of hole to the edge of the plate shall not be less than 1.75 times the diameter of the bolt. Tolerance of all hole diameters and spacing shall be as indicated on the project plans or in the Special Provisions. Plates 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 foot -pounds and a maximum of 300 foot - pounds. For power -driven tools, the hold- on period may vary from two to five seconds. The bolts for aluminum structural -plate sections shall be torqued during installation to a minimum of 100 foot -pounds and a maximum of 200 foot -pounds. Bolts shall be of sufficient length to provide a full nut. After structural plate pipe has been erected, all spots where damage has occurred to spelter shall be given two coats of an approved hot asphalt paint, or shall be wire brushed and given two coats of zinc paint, as specified in Section 1002 of the specifications, as directed by the Engineer. TABLE OF CONTENTS INDEX