Mechanical Behaviour of Artificially Frozen Ground: Experimental Observations and Modelling

人工冻结是近年来发展起来的一种临时地基加固技术，已成功地应用于不同岩土条件下的地下工程。这一成功主要是由于它对环境的影响最小，以及在了解冻土行为方面取得的进展。由于控制方程的强非线性和它们的互反耦合，分析冻土的热-水-力耦合行为需要采用数值技术。冻土行为的本构模型已经开发并实现了不同程度的复杂程度，这取决于它们的特定应用目的。然而，对于完全耦合的THM方法，包括瞬态效应在内的坚实框架尚未建立，并且在冻结/未冻结地面的实验表征和本构建模方面仍有基础研究的余地。

Artificial Ground Freezing (AGF), a newly developed system used as a temporary ground improvement, has been successfully exploited for underground construction under different geotechnical conditions and all over the world. This success is mainly due to its minimal impact on the environment as well as to the progress made in the understanding of the behaviour of frozen soils. Owing to the strong non-linearity of the governing equations, and their reciprocal coupling, the analysis of the Thermo-Hydro-Mechanical (THM) coupled behaviour of frozen soils requires the adoption of numerical techniques. Constitutive models for the behaviour of frozen ground have been developed and implemented with various degrees of sophistication, depending on their particular application purposes. However, a solid framework including also transient effects has yet to be established for fully coupled THM approaches and there is still scope for fundamental research to be carried out on experimental characterisation and constitutive modelling of frozen/unfrozen ground.