Field monitoring of soil-moisture to understand the hydrological response of a road-cut slope

Pradhan, S.; Toll, D.J.; Rosser, N.J.; Brain, M.J.

Abstract

Rainfall and slope-cutting for road construction are two key landslide causative factors in Nepal, but how they interact to cause failures is poorly understood. To improve understanding of the effects of cut slopes during rainfall, geotechnical investigations and field monitoring were conducted in a mountainous district, Sindhupalchowk, located in central Nepal. This paper presents the results of the field-investigations and the measurements of volumetric water content obtained from the sensors installed in the study-site. Field-based evidence suggests that the slope that was cut for road construction during the dry period remained stable due to the presence of soil suction, which imparted additional strength to the soil. At the start of the monsoon, infiltration of rainwater caused saturation of the soil at shallow depth, consequently causing loss of suction and reduction of the soil strength. The presence of the road-cut in the hillslope resulting in steeper slopes then promoted the failure. These observations suggest that the presence of road-cuts in the hillslopes can cause landslides even during non-exceptional rainfall events.

Citation

Pradhan, S., Toll, D., Rosser, N., & Brain, M. (2020). Field monitoring of soil-moisture to understand the hydrological response of a road-cut slope. In R. Cardoso, C. Jommi, & E. Romero (Eds.), 4th European Conference on Unsaturated Soils (E-UNSAT 2020). EDP Sciences. https://doi.org/10.1051/e3sconf/202019501029

• Online Publication Date: Oct 16, 2020
• Publication Date: 2020
• Deposit Date: Oct 20, 2020
• Publicly Available Date: Oct 21, 2020
• Publisher: EDP Sciences
• Series Title: Field studies and engineering applications
• Series Number: 195
• Book Title: 4th European Conference on Unsaturated Soils (E-UNSAT 2020).
• DOI: https://doi.org/10.1051/e3sconf/202019501029
• Public URL: https://durham-repository.worktribe.com/output/1655674