P1 LOCATING TILE LINES 1 LS - Lump Sum Estimated Quantity of 1 STA The Contractor shall excavate and expose existing tile on both sides of Ramp D at the I-80/I-280 interchange to verify alignment and facilitate proper connection. No installation work shall begin until the tile configuration has been field-verified and approved by the Engineer. Contractor shall plug all existing tile ends to be abandoned by pricing a dry bagged concrete mix into each open end. Concrete shall be hand-picked to ensure a tight seal that prevents water intrusion. P2 INTAKE, STANDPIPE, 4 IN, AS PER PLAN 1 EA - Each Estimated Quantity of 2 Each Install orange perforated standpipe at locations as directed by the Engineer to allow for future inspection and maintenance access. P3 SUBDRAIN, PLASTIC PIPE, 4 IN DIA 1 LF - Linear Foot Estimated quantity of 120 LF. Furnish and Install non-perforated, dual-wall HDPE subdrain pipe In accordance with Section 4146 of the Iowa DOT Standard Specifications. Removal and disposal of existing subdrain tile and accessories shall be considered Incidental. Include all fittings, adapters, and accessories required for alignment, bends, or directional changes, A 4-Inch diameter Is anticipated; however, actual pipe size shall be verified In the field prior to installation, Refer to Item 1 - Locating Tile Lines for related requirements. The 4-inch plastic subdrain pipe installed within the casing shall be a single, continuous section without any joints, This Is to ensure long-term structural Integrity and to prevent potential infiltration, separation, or blockage inside the casing. The Contractor shall submit manufacturer specifications, product data sheets, and representative samples for all 4-Inch plastic subdrain pipe, Including all fittings, joints, and related components for review and approval by the Engineer prior to Installation. Measurement and Payment; Per Linear foot, Payment Includes all pipe, fittings, collars, labor, equipment, and materials for complete Installation, P4 TRAFFIC CONTROL 1 LS - Lump Sum Provide all labor, materials and equipment necessary for traffic control, work on I-80, I-280, or associated ramps shall not involve shoulder work or lane closures. All traffic control operations shall conform to the approved traffic control plan. Modifications require prior written approval from the Engineer. P5 MOBILIZATION 1 LS - Lump Sum P6 STEEL ENCASEMENT FOR SUBDRAIN TILE, TRENCHLESS, 8" DIA. 1 LF - Linear Foot Estimated amount 86 LF. Install an 8-inch minimum diameter steel casing pipe under Ramp D using trenchless methods. Casing shall conform to Section 2553.02, B of the lowa DOT Standard Specifications and have a minimum wall thickness of 0.375 inches. Installation shall follow Standard Road Plan DR-302. Include all labor, materials, and equipment to complete the work, including casing pipe, boring/jacking operations, jacking and receiving pits, and restoration. The Contractor shall install casing end seals on all newly installed 8" DIA. STEEL ENCASEMENT FOR SUBDRAIN TILE, TRENCHLESS. End seals shall be properly secured and sealed to prevent the infiltration of soil, water, or debris into the casing. The steel encasement shall be installed as a single, continuous section with no joints, welds, or couplings permitted beneath the roadway. All connections, if required, must be located outside the roadway limits. All proposed connections to the steel encasement-including joints, welds, or couplings-shall be submitted to the Engineer for review and written approval prior to any fabrication or installation. All tile work beneath Ramp D, from toe-of-foreslope to toe-of-foreslope, shall be completed using trenchless methods. Measurement and Payment: Per linear foot. Payment includes full compensation for installation and all incidental work in compliance with Section 2553. P7 PERIMETER AND SLOPE SEDIMENT CONTROL DEVICE, 12 IN. DIA. 1 LF - Linear Foot Estimated amount 100 LF P8 REMOVAL OF PERIMETER AND SLOPE OR DITCH CHECK SEDIMENT CONTROL DEVICE 1 LF - Linear Foot
