Análisis de estabilidad Post-deslizamiento por medio de modelación numérica tridimensional de la ladera del cerro casual del Cantón Alausí provincia de Chimborazo

Abstract

The landslide that occurred on March 26, 2023, in the Alausí Canton caused significant human and material losses, affecting the entire population. This study aims to analyze the current stability of Cerro Casual in light of the potential for a new landslide, using three-dimensional numerical modeling through the MIDAS GTS NX software. The research began with the collection of geological and geotechnical data. Using empirical correlations, geomechanical soil parameters were estimated, including elastic modulus, Poisson's ratio, cohesion, internal friction angle, and unit weight. This process was essential, as a back-analysis was conducted to calibrate the model by reducing cohesion and internal friction angle through correlations that consider the increase in soil moisture. With these parameters, 3D finite element numerical models were developed for the conditions before and after the landslide. This advanced modeling tool enabled precise simulation of Cerro Casual within the study area, considering all physical phenomena present in the affected zone. The models included steady-state seepage analyses to estimate pore water pressures. Additionally, the Strength Reduction Method (SRM) was applied to identify the potential failure mechanism and determine a safety factor that closely reflects real site conditions. Finally, a pseudo-static analysis was performed to evaluate slope stability under potential seismic events. This assessment was critical to determine the safety factor under dynamic conditions and to understand the current slope stability, providing the basis for recommending control measures to warn the population and prevent another disaster.