NS-10 Junction Chamber (1990)
Milwaukee, Wisconsin
Michels Pipeline Construction Company, Inc.
A frozen earth cofferdam, approximately 30 feet in diameter by 70 feet deep, was formed for the construction of a sewer junction chamber. This chamber was unique in that three openings were mined through the frozen earth. One opening was designed to connect the junction chamber with a subsurface sewer structure previously built.
Another opening was created when an 8-foot diameter tunnel was driven into the frozen earth. Ground freezing also was used to provide tunnel support during mining. This use of ground freezing provided a watertight connection between the tunnel and junction chamber.
The third opening was another tunnel used in a river crossing adjacent to the junction chamber. The river crossing used steel sheeting for excavation support. Prior to freezing, the steel sheets were driven into the area to be frozen. After freezing, the steel/frozen earth joint provided a safe watertight connection between the junction chamber and river crossing tunnel.
Milwaukee, Wisconsin
Michels Pipeline Construction Company, Inc.
A frozen earth cofferdam, approximately 30 feet in diameter by 70 feet deep, was formed for the construction of a sewer junction chamber. This chamber was unique in that three openings were mined through the frozen earth. One opening was designed to connect the junction chamber with a subsurface sewer structure previously built.
Another opening was created when an 8-foot diameter tunnel was driven into the frozen earth. Ground freezing also was used to provide tunnel support during mining. This use of ground freezing provided a watertight connection between the tunnel and junction chamber.
The third opening was another tunnel used in a river crossing adjacent to the junction chamber. The river crossing used steel sheeting for excavation support. Prior to freezing, the steel sheets were driven into the area to be frozen. After freezing, the steel/frozen earth joint provided a safe watertight connection between the junction chamber and river crossing tunnel.