The South Tail Tunnel of the No. 7 Subway Line in NYC recently required ground freezing and permeation grouting to provide ground stabilization and groundwater cutoff.
Read MoreRecovery of Tunnel Boring Machine
Ground freezing, using liquid nitrogen to create a strong watertight frozen earth envelopes around a Tunnel Boring Machine…
Read MoreNS-10 Shafts and Ancillary Structures (1990)
Two deep shafts and three frozen earth cofferdams were constructed in highly organic silt deposits in the downtown area of Milwaukee, Wisconsin. A numeric thermal analysis was used to model the freezing time and proved to be a successful tool in predicting the advance and final thickness of a frozen wall.
Read MoreBushwick Shaft 20B
Installed and maintained a ground freezing system around the perimeter of the 46-foot diameter shaft, extending approximately 300 feet into bedrock…
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…
Read MoreGround Freezing for Tunnel Support
This paper discusses the construction approach to using ground freezing for the first time to freeze a substantial length of tunnel for TBM mining. Techniques including the complex drilling program, aluminum refrigeration pipes, and instrumentation are discussed. Read More
