Low-temperature ground freezing methods for underground construction in urban areas

Abstract

Artificial ground freezing (AGF) is a commonly used ground improvement technique. It can be applied in diverse construction projects in dense populated urban areas where other methods are inapplicable. In this article are discussed several methods of ground freezing, such as: “brine” freezing, liquid nitrogen freezing, solid carbon dioxide freezing. Their advantages and disadvantages are indicated. For solid carbon dioxide freezing, several approaches are presented. One of them is a brine “aftercooling” freezing method. They can significantly increase efficiency of ground freezing and reduce its cost.