Summary of Specifications:
The work consists of constructing cast in place concrete retaining walls (1,569 CY of Concrete Class D and 191,306 lbs of reinforcing steel) along the north and south banks of the Big Thompson River at CR 29 downstream from the existing bridge and along the south bank of CR 22H upstream of the bridge (77 CY of Concrete Class D and 9,013 lbs of reinforcing steel). Embankment riprap (270 CY) is planned along the south bank of CR 22H upstream of the bridge. The CR 29 walls will support a new reconstructed asphalt pavement section (1,004 tons of HMA and 1,029 tons of ABC) as well as new concrete gutters, inlets, and culverts (1,161 LF of 2’ Gutter Type 2 and 113 LF of 18” RCP) for roadside drainage. Guardrail (572 LF of G/R Type 3 and 458 LF of Type 3 Bridge Rail) will be incorporated along the CR 29 segment. An MSE wall (480 SF) is proposed on CR 22H. Rockfall mitigation is required on the cliff faces adjacent to CR 29 and 22H. At CR 31D, the work consists of structure excavating and backfilling the bridge abutments (691 CY), reconstructing the bridge approach slabs (46 CY of Concrete Class D), repairing damages to the bridge girders and deck (Cement Grout, Epoxy Resin Injection, sawing/sealing joints, clean bearing devices, etc), raising the road profile between the Handy Ditch and CR 31D Bridge (986 CY of Embankment Material), paving the bridge approach lanes (191 tons of HMA and 498 tons of ABC), and roadside ditch grading. One travel lane must remain open at all times during CR 31D work.