关键词: 土工格室加筋土挡墙, 冻融循环, 多场耦合, 冻胀变形, 数值模拟, 模型试验

Abstract: To investigate the response patterns of temperature, moisture, deformation, and stress fields in geocell-reinforced soil retaining walls subjected to freeze-thaw cycles, a model test was conducted based on a new project at Hashilegen Daban along the G217 Dushanzi-Kuqa Highway. A coupled hydrothermal-mechanical numerical model for the geocell-reinforced retaining wall was developed using the secondary development module in COMSOL. This study analyzed the effects of freeze-thaw cycles on the internal temperature field, moisture distribution, and stress-strain behavior of geocells post-construction. Experimental results were compared with simulation results to validate the findings. The findings indicate that the temperature field exhibits a curvilinear pattern influenced by freeze-thaw cycles, showing notable hysteresis with increasing depth. Temperature gradients induce moisture migration toward the freezing front, resulting in the formation of a frozen layer of specific thickness and moisture accumulation at the wall toe. Combined moisture accumulation and phase-change expansion drive asymmetric frost heave and thaw settlement, with the most significant displacement occurring from one-third of the wall height to the top. The strain distribution exhibits a convex nonlinear pattern, indicating that the middle-lower and near-surface zones become mechanically vulnerable. Geocells withstand frost heave pressure during cold seasons and earth pressure during warm seasons, regulating stress distribution through bidirectional restraint, thereby effectively mitigating wall deterioration.

Key words: geocell-reinforced earth retaining wall, freeze-thaw cycles, multiphysics coupling, frost heave deformation, numerical simulation, model test