Environ. Res. Commun.1(2019)125003https://doi.org/10.1088/2515-7620/ab50f6PAPERComputational and experimental study of a hydro-dynamicallandslide model based on laboratoryflume tests

Abstract

Hydrological factors such as volumetric water content(VWC)and pore-water content(PWC)havebeen cited widely as significant factors that trigger slope failures especially shallow landslides anddebrisflows. Over the years, researchers have studied these processes using a range of physically-basedmodels which in many occasions are either too complex incorporating very many parameters or fail tomimic realfield conditions. The principal objective of this study was to derive and incorporate a set ofphysically-based equations that describe the dependence of slope failures at laboratory scale on VWCinto a factor of safety expression herein referred to as the hydro-dynamical landslide model. Themodel was validated by a series of physical tests on soil samples in the laboratory using the Chep-flume. Results showed a close agreement between computational and experimental data, confirmingthe hypothesis that cohesion, internal friction angle and pore-water pressure are modulated by VWCespecially for slopes with sandy-loam soils. More so, rapid change of soil water content was observedto accelerate build-up of negative pore-water pressures(PWP)which triggers slope failure. Apart fromgiving a simplified expression for the factor of safety, the proposed model circumvents the difficultiesassociated with tedious procedures employed in the measurement of cohesive stress by limiting thetests to only three sets of parameters i.e. VWC, PWP and displacement.