Y--Construct Canton Dam Auxiliary Spillway at Canton, Oklahoma.

The Auxiliary Spillway Channel Excavation Phase II project at Canton Lake, Oklahoma removes the remaining soil plug that prevents lake flows into the new auxiliary spillway (currently under construction). This is a fully-designed construction project (Design-Bid-Build) and will be solicited as a single phase Request for Proposal (RFP). Work also required excavating and/or re-shaping some sections of the existing dam embankment (both lake side and downstream side). Rock spalls, bedding, and rip rap placement on both embankment and channel slopes is required. Diaphragm walls shall be constructed to tie original (primary) spillway walls to the new auxiliary spillway walls. The diaphragm walls will be cast-in-place, reinforced concrete walls by slurry-trench method using polymer slurry. The diaphragm wall will be stabilized by post-tensioned anchors composed of high strength pre-stressing steel strands. Anchors shall be drilled through soil or rock and grouted in place. A cofferdam (potentially between 13 to 21 feet high) and lateral support berm (approximately 35 feet high) shall be constructed to support the diaphragm wall tie-in. Appropriate dewatering efforts for deep-hole and near-lake excavations will be necessary. Dam safety instrumentation such as toe drain systems shall be modified and/or installed as specified in the contract documents. Disposal locations of soil plug material will need grass applications as specified within the contract documents. When the soil plug removal is complete, a survey shall be used to verify excavation is complete within acceptable tolerances, per the contract documents. This project will be solicited as quote mark unrestricted quote mark with no small business set-asides: a small business subcontracting plan will be required prior to award. The applicable NAICS code is 237990. Range of magnitude is $25M-$50M. The product service code (FSC) is Y1KA.