Analysis of the triggering mechanism of landslide in the village Podi, Montenegro

Abstract

Frequent landslides in the flysch zones along the Adriatic coast commonly develop on the contact between the sound flysch and Quaternary sediments. The reason for this is most often the increased pore pressure and degradation of material due to inadequately regulated surface and groundwater. A case of one such landslide in the south-western part of Montenegro is presented in this paper. The disposal of construction waste materials above the location of the village Podi was followed by the occurrence of a landslide which affected 3.5 ha of slope and damaged 27 houses in the village. In the course of legal proceedings initiated against the contractor, a question arose of whether the deposited material could have triggered the landslide. Response to this complex question required a multidisciplinary approach, including also a numerical parametric analysis. The results of such analysis indicated that the improper depositing of material above the village induced the landslide activation for two reasons: an increase in shear stress and a change in the natural groundwater regime, which in turn affected elevation in the pore water pressure. Numerical analyses indicated that with a moderate water table rising, the factor of safety decreased by some 20%, which in case of an already conditionally stable slope is sufficient to initiate the terrain movement and formation of a landslide on a wider area.