Rock Island Wet Weather Treatment Building Support of Excavation

At the Rock Island Wet Weather Treatment Plant, the new solids handling building was placed adjacent to the existing clarifiers, administration building, and other structures that were scheduled to remain in place.  In order to construct the 24 feet deep new building, a complex earth retention structure was required.  Helm constructed a steel sheet piling cofferdam with 36” wide flange beam walers and 26” diameter pipe struts to allow for excavation and then construction of the new facility.