Ground Freezing

Photos

Formation Freezing for a Tunnel Receiving Shaft at Bergen Point. (Courtesy of Keller, North America)

Installation of Temporary Liner in a Frozen Earth Adit. (Courtesy of Keller, North America)

Excavation of Frozen Adit, First Street Tunnel, Washington, D.C. (Courtesy of Keller, North America)

Frozen Tunnel Cross Passage, Northgate Link Tunnel, Seattle, Washington. (Courtesy of Keller, North America)

Frozen Tunnel Using Sequential Excavation Method, East Side Access New York City. (Courtesy of Keller, North America)

Coolant Distribution Manifold in Freeze Pipe Cellar, White County Coal, Indiana. (Courtesy of Keller, North America)

Instrumentation - Coolant Flow Rate Monitoring. (Courtesy of Keller, North America)

Excavation of Frozen Launching Shaft, Bergen Point Wastewater Treatment Plant Long Island, New York. (Courtesy of Keller, North America)

Excavation of Frozen Shaft, Queens, New York. (Courtesy of Keller, North America)

Excavation of Receiving Shaft. (Courtesy of Keller, North America)

A) Drilling and Installation of Freeze Pipes, Shaft 18B-1 Queens, New York. (Courtesy of Keller, North America)

B) Drilling and Installation of Freeze Pipes, Shaft 18B-1 Queens, New York. (Courtesy of Keller, North America)

Drilling and Installation of Freeze Pipes, Hutchinson, Kansas. (Courtesy of Keller, North America)

Instrumentation - Ground Temperature Monitoring Pipe. (Courtesy of Keller, North America)

Polyurethane Insulation during Frozen Shaft Excavation. (Courtesy of Keller, North America)

Overview

Ground Freezing System at Eastside CSO, Portland (Courtesy of Keller, North America)

Artificial Ground Freezing (AGF) is an environment-friendly technique often applied in geotechnical applications, such as tunnel construction under difficult geological and hydrological ground conditions, for excavation support and groundwater control. Through transforming pore water into pore ice by means of withdrawing heat from the soil, the freezing process improves significantly its strength and impermeability and therefore provides a local supporting structure.

It is a promising alternative method to water-tightening technologies since the frozen ground formation withstands high water pressure.

Ground freezing has proven itself as an effective and versatile solution for open excavation support and groundwater control across various ground conditions. It excels in providing groundwater isolation and structural support, especially in deep excavations, challenging ground conditions, or when traditional ground improvement methods are not feasible due to access constraints. This technique becomes crucial for deep excavation projects, where managing groundwater and ensuring stability against the earth's pressure are paramount. It creates a solid, frozen barrier that mitigates risks associated with soil shifts or collapses, enhancing safety and control.

The method is particularly beneficial for underground projects, offering a cost-effective solution by leveraging refrigerants like brine and liquid nitrogen. Brine is suitable for long-term freezes, while liquid nitrogen allows for rapid ground stabilization, showcasing ground freezing's adaptability to various project needs.

REFERENCES

Chang, D. K., & Lacy, H. S. (2008). Artificial ground freezing in geotechnical engineering, 6th International Conference on Case Histories in Geotechnical Engineering, Arlington, VA, August 11-16, 2008, pg.1-11, Paper No. 7.56a.

Son, Y., Choi, H., & Ko, T. Y. (2018). Estimation of the amount of refrigerant in artificial ground freezing for subsea tunnel. Journal of Korean Tunneling and Underground Space Association, 20(2), 255-268.

Zhou, M. M., & Meschke, G. (2014). Numerical modeling of artificial ground freezing: multiphase modeling and strength upscaling. Ground Improvement and Geosynthetics, GSP 238, American Society of Civil Engineers, Reston, VA, 209-219.

Classes

Sustainability