Study on Subgrade Performance Evolution and Geocell-Reinforcement Effect of Subgrade in a Seasonal Frozen Area

Seasonally frozen soil is widely distributed all over the world. The change of the mechanical properties of the soil in the seasonal frozen area under the actions of freezing-thawing cycles are studied in this paper. Research show that pavement rebound deflection and tensile stress in the pavement both increase with the increase of freezing-thawing cycles times, and the overall performance of the subgrade and the pavement decreases under the actions of freezing-thawing cycles. In order to improve the strength and rigidity of the subgrade in seasonal frozen area, geocell is used in the subgrade. Geocell plays a role of "net bag effect" in the subgrade. Despite undergoing the actions of freezing-thawing cycles, when the subgrade is reinforced with geocell, the pavement rebound deflection reduced by 17.3% compared with that in Condition A. The application of geocell improves the bearing capacity of seasonal frozen soil and the stiffness of the subgrade.