Stability analysis of the Dubičná landslide (Czech Republic) considering the effect of temperature on the available shear resistance

Temperature variations, within the typical range experienced in temperate climates, have been shown to influence the shear strength of clay soils, with the effect depending on factors such as soil mineral composition, confining stress, and shear rate. Seasonal temperature fluctuations and long-term climatic trends propagate from the atmosphere into the subsurface, attenuating and lagging with depth. In the upper few meters, where landslides frequently occur, seasonal temperature variations of 2–5 °C are common.

We present field monitoring data from the Dubičná landslide, a slow-moving, clay-rich (primarily illitic) roto-translational slide in the Czech Republic. The landslide exhibits displacement rates of a few millimetres per year and displays a seasonal pattern not entirely attributable to precipitation trends. Using ring-shear experiments on shear-zone samples, we investigated the influence of temperature on the residual shear strength under different conditions. A linear relationship between temperature and shear strength was identified, indicating mild strengthening at higher temperatures under low shear rates.

Slope stability analyses, incorporating air and subsurface temperature data, were performed for current temperature conditions and future projections under climate change scenarios. The results indicate that temperature effects on the factor of safety are modest, with a slight stabilising influence due to thermal strengthening. However, fully understanding the role of temperature in the stability of clay slopes requires further experiments and advanced modelling to account for the complexities of thermo-hydro-mechanical coupling and atmosphere-ground interactions.