Soil freezing is a technique for temporary soil reinforcement by creating an ice-soil structure in the ground. The concept is to convert pure water into ice. Freezing is obtained by circulation of liquid nitrogen or brine in closed pipes placed in the ground, or by a combination of both methods. BAUER Spezialtiefbau GmbH owns a high level knowhow and worldwide experience in the various ground freezing fi elds. Frozen ground may be used to create solid, load resistant and watertight structures for tunneling works, cross passages between tunnels, pits and shaft excavations and TBM break-in or rescue.
There are two different freezing methods which can be used for soil freezing. The direct method is freezing with liquid nitrogen (lN2). This method takes a short freezing time but it has high energy and maintenance costs. The indirect method is freezing with liquid brine, which offers low energy and maintenance costs. It takes around 20 to 30 days for freezing the ground – but this method is also suitable for confi ned spaces. The so-called mixed method is a combination of freezing with liquid nitrogen and brine.