عنوان مقاله [English]
Artificial Ground Freezing is a novel, advanced, economic and eco-friendly technique in order to improve soil properties and support soil bulk. The pure water within the soil freezes and becomes a strong and waterproof material. Therefore, the frozen soil is so strong which can be used as a temporary soil support system in underground construction. In this paper, three-dimensional finite element method for frozen soil wall was simulated through modified Mohr-Coulomb constitutive modeling method. This model was verified by numerous triaxial compression tests in geotechnical laboratory of the University of Tabriz, and parametric study of frozen soil wall was performed. It is worth mentioning that this research was implemented as a case study of line 2, Tabriz urban subway and all of the specimens obtained from line 2 boreholes. Also, to verify numerical model precisely, one physical testing model was built after inducing boundary condition and parametric analyzing. In this study, the effect of temperature of frozen soil, surcharge intensity and depth of excavation on the stability of frozen soil wall were investigated. All of the simulations were performed via ABAQUS software. Results show that, lateral displacement of the wall inward excavation reduces with frozen soil wall temperature, and this reduction at wall supports is more than the middle. Increasing of surcharge in the middle of the wall leads to increase in lateral displacement of frozen soil wall inward excavation which is larger in the middle. Also, increase in depth of the excavation leads to increase in lateral displacement of the frozen soil wall inward excavation, especially in the middle of the wall. Moreover, according to results, surcharge intensity and excavation depth are more effective parameters than frozen soil wall temperature. In addition, frozen soil structures can have high ductility by accurate design. As a conclusion, this technique is recommended as an elaborate and reasonable method of temporary soil support system.