U.S. Army Corps of Engineers Olmsted, Illinois, United States
Constructing the largest civil works project ever undertaken by the U.S. Army Corps of Engineers

Constructing a mega project on the busiest stretch of inland waterway in the United States
An Alberici joint venture constructed the $2 billion Olmsted Dam at a point on the Ohio River where more annual commercial tonnage passes than any other in the country. The Olmsted Dam project included installation of five 110-foot tainter gates, a 1,400-foot navigable pass section with 12 monoliths consisting of 140 wicket gates, and a fixed weir that ties the dam into the Kentucky bank. Serving as a replacement for Locks and Dams 52 and 53, which were originally constructed in 1929, Olmsted Dam significantly improves navigation and safety along this key U.S. inland waterway.

Building massive structures on land and placing them in the water with incredible precision
Alberici used an onsite concrete batch plant to produce several precast concrete shells, the largest of which weighs nearly 5,000 tons. The shells are approximately 100 feet wide, 100 feet long, and range in height from 30 to 75 feet. They were lifted by a massive gantry crane and moved onto a skidway, where they were then transported to the river’s edge. From there, a catamaran barge transported the shells out into the river where they were lowered onto an underwater foundation using high-tech sonar, video-imaging, and real-time kinetic GPS. Once the shells were set, tremie concrete was pumped into the area under the shells to form a continuous bond with the foundation.

Innovative methods and one-of-kind equipment
Olmsted Dam was constructed using an innovative “in-the-wet” method, which eliminated the need for a traditional cofferdam and minimized impacts to existing river traffic and the environment. The Alberici team self-performed more than 95 percent of the entire project using highly specialized equipment for heavy lifting, pile driving, setting of large concrete shells, and scour protection of the river bed. The project’s 5,300-ton gantry crane was the largest of its kind and the “aqua-digger” excavator barge, with capabilities of digging in 80 feet of water, was one of only two in the world.

Industry-leading safety performance
In addition to being the largest civil works project ever undertaken by USACE, Olmsted Dam is the only Illinois construction project to ever achieve “Star” certification from the OSHA Voluntary Protection Program (VPP). OSHA VPP “Star” certification is among the highest honors for safety a project can receive.