Analysis and Remedies for Landslides Including Vegetation: A Case Study in Lebanon

Abstract

This paper aims to study and analyze the instability of slopes, their causes and possible remedies. The studied slope is located in Lebanon, and it is regularly subjected to slope instability in the rainfall season. Based on different boreholes results for the same site, two models were modeled using Plaxis and Talren, they were both studied under the effect of water, excavation and seismic load. The results show that the water is a principle cause of slope instability, by decreasing the shear parameters of soil or by the inducing pore pressure due to running water between layers. Many remedies were applied, and their results were analyzed and studied. Soil reinforcements, nails and piles, were applied and as water content increased, the number of reinforcement needed was high. Vegetation and drainage are more efficient when it comes to water problems. Both vegetation and drainage were modeled and the number of needed reinforcement decreased significantly assuring their advantages alongside with the reduction of the remedy price and being environmental friendly.

Landslide Hazard and Risk Level Assessment of Quarried Slopes in Lebanon using Drone Imagery. (c2020)

“…Ismail et al (2014) studied the stability of a 20 meters high slope in silty sand deposits under seismic loading using finite difference models in FLAC 3D and showed how soil cohesion, friction angle, and earthquake frequency affect the stability. Fawaz et al (2014) and Fawaz et al (2017) used finite element models and limit equilibrium analysis to show that high intensity rainfall events as well as a highway cut-slope excavation tremendously decreases the general stability of the natural slope. They highlighted the effects of the triggering factors, namely earthquake loading and highway excavation, on the instability of the natural ground during dry and rainy seasons.…”