McNary Dam Beam Upgrade

McNary Dam, located in Umatilla County, Oregon stretches 1.4 miles in length and stands 200 feet tall. The Army Corp of Engineers is planning an upgrade of the gantry crane located at the dam and to accomplish this a series of existing concrete beams would need to be strengthened to hold the additional weight.

STRUCTURAL was hired to perform concrete enlargement at 48 existing beam locations to support the new crane. The team subcontracted a company to construct access platforms using specialized bridge truss brackets for the work areas. In addition, extensive protection was put in place to prevent disrupting or harming the water and natural environment.

Once the site was prepped, the team drilled holes for epoxy dowels and used electric chipping guns to prepare the existing concrete beam surfaces. Reinforcing steel was installed along with formwork and the concrete was pumped. The access platforms were removed once the repairs were complete.

For this design-build project, STRUCTURAL TECHNOLOGIES worked with the Army Corp of Engineers to value-engineer the enlargement design from impacting 3 sides of the beam to only adding concrete and reinforcement to 1 side of the beam. The 1-sided enlargement streamlined the project in the field and optimized the construction schedule.

The project was safely and successfully completed nearly three weeks ahead of schedule and the dam remained operational throughout construction.