TY - JOUR
T1 - Hydro-mechanical analysis of a surficial landslide triggered by artificial rainfall
T2 - The Ruedlingen field experiment
AU - Sitarenios, Panagiotis
AU - Casini, Francesca
AU - Askarinejad, Amin
AU - Springman, Sarah
N1 - Accepted Author Manuscript
PY - 2021
Y1 - 2021
N2 - This paper interprets the hydromechanical behaviour of a steep, forested, instrumented slope during an artificial rainfall event, which triggered a shallow slope failure 15 h after rainfall initiation. The soil's mechanical response has been simulated by coupled hydro-mechanical finite-element analyses, using a critical state constitutive model that has been extended to unsaturated conditions. Failure occurs within a colluvium shallow soil cover, characterised as a silty sand of low plasticity. The hydraulic and mechanical parameters are calibrated, based on an extended set of experimental results, ranging from water retention curve measurements to triaxial stress path tests under both saturated and unsaturated conditions. Rainfall is simulated as a water flux at the soil surface and suitable boundary conditions account for the hydromechanical interaction between the soil cover and the underlying bedrock. The results are compared with field data of the mechanistic and the hydraulic responses up to failure and are found to provide a very satisfactory prediction. The study identifies water exfiltration from bedrock fissures as the main triggering agent, resulting in increased pore pressures along the soil-bedrock interface, reduced available shear strength and cause extensive plastic straining, leading to the formation and propagation of a failure surface.
AB - This paper interprets the hydromechanical behaviour of a steep, forested, instrumented slope during an artificial rainfall event, which triggered a shallow slope failure 15 h after rainfall initiation. The soil's mechanical response has been simulated by coupled hydro-mechanical finite-element analyses, using a critical state constitutive model that has been extended to unsaturated conditions. Failure occurs within a colluvium shallow soil cover, characterised as a silty sand of low plasticity. The hydraulic and mechanical parameters are calibrated, based on an extended set of experimental results, ranging from water retention curve measurements to triaxial stress path tests under both saturated and unsaturated conditions. Rainfall is simulated as a water flux at the soil surface and suitable boundary conditions account for the hydromechanical interaction between the soil cover and the underlying bedrock. The results are compared with field data of the mechanistic and the hydraulic responses up to failure and are found to provide a very satisfactory prediction. The study identifies water exfiltration from bedrock fissures as the main triggering agent, resulting in increased pore pressures along the soil-bedrock interface, reduced available shear strength and cause extensive plastic straining, leading to the formation and propagation of a failure surface.
KW - landslides
KW - numerical modeling
KW - partial saturation
UR - http://www.scopus.com/inward/record.url?scp=85100307090&partnerID=8YFLogxK
U2 - 10.1680/jgeot.18.P.188
DO - 10.1680/jgeot.18.P.188
M3 - Article
AN - SCOPUS:85100307090
SN - 0016-8505
VL - 71
SP - 96
EP - 109
JO - Geotechnique
JF - Geotechnique
IS - 2
ER -