for Highway Construction Page 365 of 71 5 SECTION 507 – BRIDGE BEARINGS
507.01 Description.
Provide and place bearings including plain unreinforced elastomeric pads, reinforced elastomeric pads with steel laminates, or polytetrafluoroethylene (PTFE) pads with stainless steel mating surface that meet AASHTO Specifications for Highway Bridges at girder supports as specified. Provide bearings with the dimensions, material properties, elastomer grade, and type of laminates specified. Show the design load specified and testing requirements. If filled PTFE sheet is used, only glass -fiber filler will be approved.
507.02 Materials.
Provide bearings as specified in: Elastomeric Bearings ............................................................................................................... 720.02 Polytetrafluoroethylene (PTFE) Bearings ................................................................................ 720.03 Provide manufacturer certificates of compliance for materials used in t he bearings.
507.03 Construction Requirements.
Fabrication. Fabricate bearings as specified in 720.02. Testing. Test materials for elastomeric bearings and finished bearings as specified in 720.02. Installation. Install bearings as specified in 720.02.
507.04 Method of Measurement.
The Engineer will measure acceptably completed work by the each.
507.05 Basis of Payment .
The Department will pay for acceptable quantities as follows: Pay Item Pay Unit Elastomeric Bearings – Plain .................................................................. Each Elastomeric Bearings – Laminated ......................................................... Each PTFE Bearings ....................................................................................... Each for Highway Construction Page 366 of 71 5 SECTION 508 – CORRUGATED PLAT E PIPE
508.01 Description.
Provide and install a steel or aluminum corrugated plate pipe arch structure as detailed or as specified. The structure must be designed in accordance with the current edition of AASHTO LRFD Bridge Design Specifications .
A.Design Computations and Shop Drawings . Submit the manufacturer’s shop drawings and design computations, in accordance with 105.02, for Engineer approval before fabrication. Ensure the shop drawings and design computations are signed and sealed by an Idaho licensed professional engineer. Ensure shop drawings include a plate layout showing installation offsets and sequence from a common reference point for all stages of construction. For single pipe arch structures with a span length equal to or greater than 10 feet measured along the centerline of roadway or a combination of pipe arches with a total out to out length equal to or greater than 10 feet measured along centerline of roadway and the distance between centerlines of pipes less than one - half the span length of the smaller pipe arch, the structure must be designed at Strength II for a standard gauge tridem axle load of 120 kips (40 kips per axle) with 4.5 foot spacing between axles.
B.Initial Load Rating. For all pipe arch structures requiring Strength II design for tridem axel as defined in 508.01.A, the supplier is required to prepare a Load and Resistance Factor Rating (LRFR) in accordance with the Idaho Manual for Bridge Evaluation and provide a Load Rating Summary (LRS) form for approval by the Department at the same time as shop drawing submittal .
508.02 Materials.
Provide material as specified in 708.20. Meet minimum thickness for all steel plates as shown in the bridge plans.
508.03 Construction Requirements.
A.General. Curve each plate to the required radius and punch the bolt holes so the sections, except the end plates, are interchangeable in the erection process. Fabricate bolt holes in accordance with AASHTO M 167 Section 6. When the completed structure is to be a full -circle pipe , curve th e plates so when they are bolted together, they form true circles of the required diameter. When the completed structure is to be a multi -centered pipe or arch, curve the plates to the required radii. Cut plates for forming skewed or sloped ends to give the angle of skew or slope specified. Ensure burnt edges do not have oxide or burrs and present a well -made finish. Install the structure in accordance w ith the p roject plans and specifications and the manufacturer’s written instructions.
Source: Idaho Standard Specifications for Highway Construction, 2023 Edition. Pages 401–401 of 768.