Construction of a 9700m, 180cm diameter effluent pipeline required tunnelling from an existing sewage treatment plant to a barrier island outfall structure. Construction of the tunnel required a launching shaft at the plant and a receiving shaft at the barrier island. Artificial ground freezing was specified as the method to provide temporary earth support and groundwater control at the launching shaft and selected by the contractor for the receiving shaft.
Read MoreFrozen Earth Cofferdam Design
Structures designed to transfer storm runoff water from surface collector systems to deep large diameter tunnels pass through a variety of subsurface soils in the Milwaukee, Wisconsin area. During construction, problems developed relative to the use of conventional earth support systems. Ground freezing was selected for temporary ground support and ground water control…
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