U.S. Bureau of Reclamation (BOR), Yuma, AZ

The BOR Lower Colorado Region is responsible for maintaining the integrity of the existing structures and conveyance system including culverts, bridges, siphons, inlets and diversions, gates, and linings. The Bypass Drain Canal, located in the Yuma, Arizona, conveys agricultural drainage flows from farmland to the Colorado River and its tributaries. The existing systems have been in continuous service for over 20 years and showed signs of deterioration and spalling along the canal at the concrete panels. GCE was contracted to perform construction work for the repair or replacement of canal lining, structures (including concrete demolition and patching), and the removal of structures as needed, at numerous areas along 16 miles of the Bypass Drain Canal.

GCE provided all labor and equipment to self-perform 100% of the work on this task order. GCE personnel provided all management including a Quality Control (QC) representative and Site Safety and Health Officer. Prior to beginning the field activities, we prepared all planning documents in-house including the Accident Prevention Plan, the Demolition Plan, the Environmental Protection Plan, and the Quality Control Plan. The QC representative also prepared the construction schedule utilizing the Microsoft Project for this time sensitive project. In addition, all construction submittals were prepared and included expansion joint material, concrete, concrete sealer, and safety ladders. The QC representative prepared daily reports of work to record any issues that pertaining to the project and to record the location and dimensions of all repair areas.

For the complete concrete replacement areas, our crews first sawcut the areas with a concrete saw and carefully removed the damaged concrete utilizing a backhoe and a loader for disposal with a dump truck. Once the demolition of each site was complete, dust abatement was accomplished with the use of our water truck and the subgrade was prepared by watering and compacting with a specialty compaction roller attached to the backhoe. Expansion material was placed per specifications and the concrete crews utilized concrete roller screeds that are ideal for sloped surfaces such as canal panels, to level and smooth the concrete surface. After the concrete cured, the joints were prepped and cleaned, and primer was applied to allow the epoxy joint sealant to adhere better.

GCE also installed 100 safety ladders along the 16 miles of the Bypass Drain Canal. Each new ladder installation involved removal of the existing damaged ladder, cleanup of any debris, hammer drilling holes into existing concrete and setting concrete anchors for bolting the new ladders.

Concrete patching was also performed in some of the spalled areas of concrete located on the wing walls and on the culvert head walls. The areas were prepped by removal of loose concrete and sandblasting any exposed rebar. For areas with exposed rebar, an epoxy coating was applied to protect the steel. The patching material was applied, and a two-part epoxy was applied to the surface.

Backfill and compaction was performed adjacent to all the canal repair areas and the areas were dressed up for final approval by BOR representatives.