ABSTRACT
The ground improvement needed for excavation of deep shafts is ideally suited for ground freezing. Ground freezing has a niche particularly in deep tunneling work because a frozen shaft can be confirmed to be adequately formed prior to excavation, whereas other ground improvement techniques cannot provide such an assurance. The design of ground improvement by ground freezing requires consideration of two distinct aspects of the performance: structural and thermal. Alternative means for ground freezing mean the technique can be deployed rapidly for short-term ground improvement projects using liquid nitrogen or for longer and larger projects using brine chillers. Some applications of geosynthetic ground improvement include soil strengthening, road base improvement, compaction aids, underfooting reinforcement, embankments over soft ground, mechanically stabilized earth, steepened slopes, and soil separation. Finally, ground freezing is relatively quiet compared to other ground improvement and foundation engineering techniques adding value to its use in urban environments.
