Artificial Ground Freezing

Definition

Artificial ground freezing (AGF) is a technique of freezing of pore water in saturated and partially-saturated soil which changes the thermal and mechanical properties such as stiffness, strength, and creep behavior of soil. This change in properties increases the load-carrying capacity of the frozen soil which is exploited in various construction works. Originally, the AGF was first developed by F.H. Poetsch in 1883. Poetsch’s process involves the circulation of a refrigerated coolant through a series of subsurface pipes to extract heat, thus converting the soil water to ice, creating a strong, watertight material. Most ground freezing systems are quite similar in principle, with subtle differences in the engineering aspects of the individual sites. The single most important component of a ground freezing system is the subsurface refreezing system, consisting of a series of refrigeration pipes installed with various drilling techniques. The quantity, spacing, depth, and...