608.01 Description. This item shall consist of the construction
of corrugated metal structural plate pipe, pipe-arc hes, and arches according to these specifications, of the type, siz e, and dimensions shown on the plans, and in conformity with the loca tions, lines, and grades shown on the plans, or as directed.
608.02 Materials. The material furnished shall be either steel or
aluminum, at the Contractor's option, and shall com ply with the following requirements: The manufacture and furnishing of structural plate shall be according to AASHTO M 167 or M 219 as amended below :
1.No metal will be accepted until after the sheet manufacturer's certified analysis and fabricator's certification h ave been received and approved by the Engineer of Materials. If the Engineer so elects, the material may be insp ected and sampled in the rolling mill or in the shop where fa bricated and a detailed chemical analysis of any heat may be requi red from the mill. The inspection, either in the mill or in the shop, shall be made under the direction of the Engineer. The Engineer shall have free access to the mill or shop for inspection and every reasonabl e facility shall be provided for this purpose. The inclusion of any ma terial or pipe that has been previously rejected at the mill or shop wi ll be considered sufficient cause for the rejection of the entire lo t.
2.A field inspection shall be made by the Engineer . The Contractor shall furnish an itemized statement of t he number and length of the plates in each shipment. Each plate included in a shipment shall comply with the requirements of thes e specifications. If 25% of the plates in any shipment fail to comply with the requirements, the entire shipment may be rejected.
3.The gauge of structural plate and radius of curv ature shall be as specified on the plans.
4.When specified on the plans, an asphalt coating complying with Subsection 606.02 shall be applied to the stru cture. 437 608.03 Construction Requirements. (a) Excavation. When a structure is to be erected in a trench or channel, the width of the excavation shall be sufficient to permit thorough t amping of the backfill material, but shall not exceed the span wi dth by more than 3' (1 m) on each side at the bottom of the trench. Si de slopes of the excavation shall not be flatter than 2:1 except whe re unsuitable material is encountered.
b.Bedding. The pipe shall be bedded in an earth foundation o f uniform density, carefully shaped by means of a tem plate supported at the desired grade, to fit the lower plate of the pipe. A minimum camber of 1% of the length of pipe shall be made to allow for settlement. The amount of camber shall be varied t o suit the height of fill and supporting soil as directed. Where rock in either ledge or boulder formation is encountered, it shall be removed to a depth of at least 12" (300 mm ) below the grade established for the bottom of the structure, and to a minimum width equal to the span. This additional excavatio n shall be backfilled with material complying with Subsection 608.03(d). If the existing material exposed at the grade estab lished for the bottom of the structure appears unstable and is of such character as to invite unequal settlement along the length of th e structure, such unstable material shall be removed as directed and the excavation shall be backfilled with gravel or other suitable m aterial as hereinafter specified and thoroughly tamped or othe rwise compacted in place to ensure a firm foundation. Any necessar y excavation below the invert of the structure shall be made acc ording to Section 801.
c.Assembly. All plates shall be unloaded and handled with reasonable care. Plates shall not be rolled or dra gged over gravel or rock and shall be prevented from striking rock or o ther hard objects during placement in trench or on bedding. Structural plate pipe shall be assembled progressiv ely according to the manufacturer's instructions starting at the downstream end with the inside circumferential laps pointing downs tream. On all plates above the invert plate or plates, onl y sufficient bolts shall be used to hold the plates loosely in positio n until assembly has been completed for four or more rings. When all pl ates are in position, all bolts not already in place shall be i nserted and the nuts 438 tightened progressively through the structure. All nuts shall be tightened a second time to a torque of not less tha n 100 foot-pounds (135 newton meters [N ·m]) nor more than 250 foot-pounds (340 N ·m). Each 20th bolt will be checked with a torque w rench that shall be furnished by the Contractor. Where t ests indicate loose bolts, the bolts in that area shall be properly tig htened and additional tests made. Standard bolts are furnished in two le ngths: the short bolts shall be placed where two plates lap and the long bolts shall be placed where three plates lap. All service bolts u sed in drawing the plates together shall be replaced with standard bol ts.
d.Backfill. Unless otherwise specified on the plans, backfill material shall be of a granular nature with a maxim um size of 3" (75 mm), free of frozen lumps, chunks of highly pla stic clay, or other objectionable matter. Materials from roadway excavation or borrow meeting these requirements may be used if ap proved by the Engineer. After the structure has been erected according to t hese specifications, backfill material shall be placed i n layers not to exceed 6" (150 mm) thickness at near optimum moistu re content and compacted. The side fill shall be placed and compa cted with care under the haunches of the structure and shall be br ought up evenly and simultaneously on both sides of the structure t o not less than 1' (0.3 m) above the top for the full length of the st ructure. Compaction equipment shall be mechanical hand tamps and rolling equipment in such combination as to provide 95% of maximum density as determined by AASHTO T 99. The Departme nt will perform acceptance sampling and testing of the comp acted backfill material in accordance with Subsection 210.10 at th e frequencies established in the Department’s Manual of Field Sampling and Testing Procedures . Pipe damaged during construction operations shall be replaced or repaired at no cost to the Dep artment.
608.04 Method of Measurement. Structural Plate Pipe, Pipe-
Arch, or Arch will be measured by the linear foot ( meter) along the bottom centerline of the structure.
608.05 Basis of Payment. Work completed and accepted and
measured as provided above will be paid for at the contract unit price bid per linear foot (meter) for Structural Pl ate Pipe, Structural Plate Pipe-Arch, or Structural Plate Arch, of the s izes specified, 439 which price shall be full compensation for furnishi ng, handling, erecting, strutting, and installing; and for all ma terials, labor, equipment, tools, and incidentals necessary to comp lete the work. Channel excavation, backfilling, and concrete and r einforcing steel for headwalls and foundations will be paid fo r as separate items as specified on the plans. Structural excavation w ill be paid for under Section 801 for the appropriate classificatio n of Excavation for Structures - Roadway. Payment will be made under: Pay Item Pay Unit __" (__mm ) Structural Plate Pipe (___Gauge) Linear Foot (Meter) __"x__" (__x__mm) Structural Plate Pipe-Arch (___Gauge) Linear Foot (Meter) __"x__" (__x__mm) Structural Plate Arch (___Gauge) Linear Foot (Meter)
Source: , Edition.