Mitigating frost heave of an expansive soil channel reinforced with soilbags: Insights from physical model tests

Abstract

Frost heave significantly affects the normal operation and long-term performance of expansive soil channels, and the soilbag reinforcement method offers a potential solution for its mitigation and control. To confirm the effectiveness of the soilbag reinforcement method in frost heave mitigation of expansive soil channels, a middle-scale model test apparatus was developed to be equipped with temperature control and water supply functions, and then two groups of physical model tests were conducted. The evolution of water and heat distribution, frost heave deformation, and surface morphology in expansive soil channels with and without soilbag reinforcement during the freezing process were carefully compared. The experimental results demonstrate that: 1) The developed apparatus presents excellent performance, which can accurately capture the freezing behavior differences between an expansive soil channel and a soilbag-reinforced channel. 2) Utilizing soilbags in expansive soil channels not only provides thermal insulation but also mitigates the segregation frost heave. 3) Soilbags have the ability to decrease water evaporation from the bagged expansive soil, effectively preventing the soil from shrinking due to water loss while also reducing uneven deformation. Furthermore, the frost heave mitigation mechanism of the soilbag-reinforced expansive soil channel was well illustrated with two idealized schematic diagrams.