a. The following specifications are intended for circular corrugated steel pipe to be used as excavation shields as required by the City of Minneapolis Public Works – Water Treatment and Distribution Services. The bid for furnishing this material shall be made on a unit basis with delivery to a designated site as noted in Section II Sub-Section 7, Delays and Delivery Failures. b. Commodity Description and Quantity i. Circular Corrugated Steel Excavation Shield Pipe, 8’ Diameter x 9’ Length ii. 120 each c. Applicable Standards i. AASHTO M36. Standard Specification for Corrugated Steel Pipe, Metallic Coated, for Sewers and Drains ii. MnDOT Specification 3226 – Corrugated Steel Pipe iii. ASTM A796, Standard Practice for Structural Design of Corrugated Steel Pipe, Pipe-Arches, and Arches for Storm and Sanitary Sewers and other buried applications d. Materials i. Corrugated steel pipe shall meet MnDOT Specification 3226 and be fabricated with ASTM A929, Fy = 33 ksi with the following dimensions: 1. Steel thickness: 12 gauge (0.109 inches, min) 2. Corrugations: 3” Pitch x 1” Depth ii. Steel Channels shall be ASTM A36, Fy = 36 ksi e. The corrugated steel shall be coated with a 2-oz. galvanized coating. f. The shields shall have two, 3” x 3.5 lb. x length, “C” channels welded to the outside, along the length of the pipe, positioned 180 degrees apart. The flat portion of the channel shall be flush against the corrugations and welded to each corrugation. g. All cuts made to the corrugated pipe shall be ground so that there are no exposed sharp edges. Note to Manufacturer about optional opening at base: No cut-out on the shield is required. This modification will be performed in the field as-needed.
