Placentia Canal Drainage Improvements-Laroche and Semken Culvert Replacement

The work to be done consists of the following generally described items: Upgrade the existing double 3’x5’ box culverts under Laroche and Semken Avenues to double 8’x5’ box culverts. The length of the proposed double box culvert is 44 linear feet at Laroche and 57 linear feet at Semken. The Base Bid includes precast box culverts. Alternate 1 includes cast-in-place box culverts. The pre-cast box culvert must utilize a “watertight” ASTM C1677 joint in lieu of the “soil tight” ASTM C990 joint that has typically been utilized locally. The cast-in-place box culvert must utilize expanding waterstop in addition to the GDOT specified exterior waterproofing. The double box culverts will be bear on a geotextile and 12 inches of #57 stone. The project will include cast-in-place concrete wing walls and aprons. A replacement stormwater pipe will be constructed and an 8” water line will be rerouted with inserta valves in manholes at Semken. Sanitary systems will not be impacted. The project will include the demolition and replacement of sidewalks and guardrails. The channel will be lined with 4” of concrete revetment fabric. The project will be performed in two phases with Semken being phase 1 and Laroche being phase 2. Phase 1 (Semken) must be substantially complete and opened to traffic before closing traffic for phase 2.

Division 31 -	Earthwork, Erosion and Sedimentation Controls.
Division 33 -	Utilities, Storm Drainage Utilities, Culverts, Ponds and Reservoirs.