ABSTRACT
Artificial ground-freezing method is an advanced ground improvement technique. It uses artificial freezing to improve soil strength and impermeability. The cold source can be divided into brine and liquid nitrogen (LN2). However, most studies focus on brine systems, the LN2 method utility and the frost heave are still not well understood. To explore the applicability and frost heave of LN2 freezing technology, a field test with LN2 freezing system is conducted. The freezing behavior and frost heave were observed according to the ground settlement and inclinometer deformation. Numerical simulations on soil frost heave were performed by PLAXIS with Frozen and Unfrozen soil model (FUS), the monitoring results are compared with numerical analysis and geophysical explorations. The results show that the LN2 methods can effectively and quickly form frozen soil walls. The thickness of the frozen soil wall reaches 1.2m in 6 days through PLAXIS FUS model back analysis. Moreover, subsurface temperature and media changes are detected by geophysical exploration, explaining the freezing results.
