冻融作用下初始含水率对膨胀土边坡稳定性的影响研究

With global warming, the area of seasonal permafrost is increasing, and the slope is highly susceptible to destabilization under the effect of freeze-thaw cycles. As a special soil, expansive soil slope is more prone to destabilization. The slope temperature, moisture content, soil pressure, and displacement are monitored in real-time under multiple freeze-thaw cycles by modeling expansive soil slopes with different initial moisture contents. The influence of initial moisture content on the stability of slopes of expansive soil is investigated by examining the variation of parameters of slopes of expansive soils with different initial moisture contents under freeze-thaw cycles. Results show that the monitoring data of expansive soil slope show periodic changes in the process of multiple freeze-thaw cycles, and first freeze-thaw has the greatest impact on slope soil. Moreover, the slope shows unidirectional freezing and bidirectional thawing, and the thawing rate is greater than the freezing rate in the freeze-thaw process. The higher the initial moisture content of the slope, the longer the time is needed to reach the freezing stability, the greater the variation range of soil pressure, and the greater the frost heave rate. In addition, there are two phenomena of "frost shrinking and thaw expanding" or "frost expanding and thaw shrinking" in the soil body of the slope with different initial moisture content, but the slope as a whole develops towards the freeing surface. Research results may provide a theoretical and scientific basis for the study of the slope stability of expansive soil in the seasonally frozen soil zone.