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ii. Replace the concrete stair at the north and south end of the spillway. <br /> iii. Replace all seals on the bascule gate. <br /> iv. Repairs to electric heaters and conduits of hydraulic cylinders. <br /> v. Repairs to hydraulic gate cylinders. <br /> vi. Specify taking of concrete cores at intervals along the stilling basin apron slab to evaluate <br /> possible slab undermining. <br /> c. South Abutment and Training Walls <br /> i. Include an alternate bid item in the contract documents for additional work to investigate <br /> the origin of the leak from the back side of the training walls. The items would include <br /> work to excavate the embankment,make repairs to back side of the wall, inject cracks, or <br /> install waterproofing measures on these walls. <br /> ii. Repair erosion and place new slopewall at the west end of the downstream training wall. <br /> d. Gated Outlet Structure <br /> i. Inject the crack and repair spalled concrete along the top of the center wall at the crack. <br /> ii. Repair spalled concrete areas located on: the south training wall near the gate; near the <br /> top of the north gate; and at a corner on the north training wall. <br /> iii. Dewater the area in front of the gates to allow a detailed investigation of the seals of bolh <br /> gates. Include an alternate bid item to replace the seals if required. <br /> iv. Placement of erosion control measures to address the scoured area downstream of the <br /> apron <br /> v. Repair, clean and paint sluice gate guides. <br /> 3. Prepare detailed plans and specifications to improve erosion control measures at the downstream left bank <br /> storm sewer. <br /> 4. Observations and Investigations <br /> a. Perform field condition survey by boat along the downstream face of the spillway in order to <br /> assess the proposed limits for the joint repairs. <br /> b. HDR Engineering will: perform site observations, investigate repair alternatives; and make <br /> recommendation for the repairs to bascule and sluice gate seals, gate hydraulic cylinders, and gate <br /> heaters. <br /> c. Monitor the performance of the membrane test area for one year. Hanson will make 3 site visits <br /> over a one-year period after construction to observe the condition of the membrane. <br /> <��'� HANSON <br /> � <br /> PSA Rev.2 3 <br />