Description
Description of Work 1. South Unit Water Control Structures and Berm Degrades a. Construct six reinforced concrete water control structures i. Excavation and removal of existing single pipe water control structures, typically comprised of either a corrugated metal pipe or precast concrete pipe as well as a concrete or metal pipe inlet structure. ii. Excavation and foundation preparation, including care of water and placement of compacted rock for reinforced concrete water control structures. iii. Construction of cast-in-place reinforced concrete water control structures, including multi-cell box culverts, headwalls, wing-walls, and slabs. iv. Purchase and installation of self-contained stainless steel slide gates and weir gates on water control structure headwalls, including such items as alignment, testing, and grouting. v. Placing structural backfill, including compacting, grading, and finishing, as well as placement of rip-rap stone. b. Degrade and of existing earthen berms and rock surfaced berms, including clearing and grubbing, material wasting or stock-piling. c. Raising existing earthen berms near new structures, including borrow, embankment placement, compaction, stone surfacing, and seeding. d. Placement of stone surfacing along the top of an existing berm. 2. Exterior Gravity Drain a. Construct a large cast-in-place reinforced concrete water control structure that utilizes a welded steel overshot gate for water control and has a bridge crossing over the structure. i. Excavation and foundation preparation, including care of water and placement of compacted rock and earthen materials. ii. Installation of sheet piling walls, parallel to the levee alignment, on each side of the structure to retain the levee embankment. Walls shall be continuous beneath the ends of the concrete structure to provide a seepage cutoff. Walls shall be PZ40 sheet piles tied to each other with walers and tie rods. iii. Construction of a soil-founded, cast-in-place reinforced concrete U-frame structure passing through the embankment. iv. Installation of a bridge across the concrete structure, consisting of four precast prestressed concrete deck beams with a cast-in-place concrete overlay. v. Design, fabrication and installation within the concrete structure of a welded steel overshot gate and appurtenances, to include hinge mechanism, wall-mounted side rubbing plates, and a manual hoist with drum and wire ropes. Provision of equipment for operating the hoist. vi. Fabrication and installation of guardrails on the concrete structure, bridge and sheet pile walls.8 vii. Placement and compaction of embankment to finished lines and grades around the structure. viii. Placement of stone surfacing, rip rap stone protection and articulated concrete block mattresses. b. Re-aligning existing earthen berms, including borrow, embankment placement, compaction, stone surfacing, and seeding. c. Placement of stone surfacing along the top of an existing berm. d. Re-aligning existing channel, including excavation and seeding. *Request for Proposal with be issued on or about 17 July 2016.