Stability and Deformation in Clayey Slopes with Varying Slope Density and Inclinations Subjected to Rainfall
A reduction in the shear strength resulting from an increase in degree of saturation and pore pressures due to the infiltration of rainwater is often cited as a trigger for shallow slope failures. Models were prepared, in this study, to examine the influence of the density of the slope forming material and the inclination of the slope on the evolution of the seepage velocity, deformation mechanisms and stability of the clayey slopes. The relative compaction of the slope forming material ranged from 60% to 85% with slope inclinations ranging from 30 to 50°. The seepage velocity was found to decrease as the depth of the wetting front increased. Furthermore, the seepage velocity along the slope was greater than the seepage velocity at the head of the slope. The seepage velocity measured with tensiometers located throughout the slope matched well with the seepage velocity determined from the wetting fronts. When the relative compaction of the slope forming material was less than 75%, the slopes would tend to settle as the material became saturated with greater volumetric strains occurring in models with lower relative compactions. On the other hand, for slopes with relative compactions greater than 75%, the infiltration of rainwater would cause the slope to swell with greater negative volumetric strains at higher relative compactions.
KeywordsRainfall-induced slope failures Clayey slopes Wetting front Deformation Seepage velocity
The authors would like to thank California State University, Fullerton Instructionally Related Activities (IRA) Grant No. 3361 for the generous support provided to purchase the materials used in this study. Additionally, the efforts of the numerous students that assisted with the model preparation and data collection are greatly appreciated.
- 2.Tiwari, B., Kawai, K., Caballero, S., Viradeth, P.: How rainfall and earthquake trigger shallow slides – experimental and numerical studies on laboratory prepared slopes. Int. J. Landslide Environ. 1(1), 109–110 (2013)Google Scholar
- 3.Tiwari, B., Lewis, A., Ferrar, E.: Experimental simulations of rainfall and seismic effects to trigger slope failures. Geotech. Spec. Publ. 231(1), 448–451 (2013)Google Scholar
- 4.Tiwari, B., Lewis, A.: Experimental modeling of rainfall and seismic activities as landslide triggers. Geotech. Spec. Publ. 225, 471–478 (2012)Google Scholar
- 5.Xue, K., Tiwari, B., Ajmera, B., Hu, Y.: Effect of long duration rainstorm on stability of red clay slopes. Geoenviron. Eng. 3(12), 1–13 (2016)Google Scholar
- 6.Tiwari, B., Caballero, S.: Experimental model of rainfall induced slope failure in compacted clays. Geotech. Spec. Publ. 256, 1217–1226 (2015)Google Scholar
- 7.Tiwari, B., Tran, D., Ajmera, B., Carrillo, Y., Stapleton, J., Khan, M., Mohiuddin, S.: Effect of slope steepness, void ratio and intensity of rainfall on seepage velocity and stability of slopes. In: Proceedings of the Geotechnical and Structural Engineering Congress, vol. 1, pp. 584–590 (2016)Google Scholar