Sheet Piling and Cofferdams

Temporary sheet piling details will not be included on the contract plans, other than general limits, locations, and cut off elevations shown in plan and section views typically as part of staged construction. The Contractor is responsible for designing, providing, installing, maintaining and removing temporary sheet piling, or cutting off temporary sheet piling left in place to the elevation. Sheeting may be driven to the penetration as determined by the Contractor’s approved design unless otherwise noted by the design plans (i.e., the plans may specify a penetration depth regardless of the design).

The area measured for payment is based on the area of earth retention, and does not include the amount needed for the toe. Vertical dimensions shall be based on the difference in ground elevations at the sheeting line, or planned foundation excavation limits at the sheeting line, whichever is less. This line typically extends from ground line on the earth pressure side, to the bottom of the excavation on the staged construction side unless other limits are designated. If retaining earth on both sides of the same sheet piling during different construction stages, the quantity and basis of payment will be based on the stage requiring the largest area of earth retention, not the sum of the areas for each stage.

Temporary sheet piling shall have a minimum nominal section modulus of 18.1 in3/ft of wall,when retaining traffic loads or adjacent to traffic. The Contractor’s plans shall show the required embedment depths, steel material grades, connection and weld details, along with required bracing, walers, tie backs and other related structural components.

The basis of payment is square foot, based on all areas retained soil, including cut slopes from the excavation limits to existing ground.

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