SLOPE STABILITY ASSESSMENT FOR COPOU EAST HILL (IASI, ROMANIA), USING MONTE CARLO SIMULATION.

Slope stability is a present-day matter, with which the authorities of many countries are confronted, due to the risks the landslides imply regarding not only the material aspect, but also the human aspect. In this paper, a study of the Copou East landslides, Iasi Municipality (Romania), was performed. Other researchers have identified on this hill, through investigations over time, prior consequent deluvial landslides over the base rock. In order to estimate the probability for further landslides to occur, a probabilistic method was applied (Monte Carlo simulation), considering a plane sliding surface. Therefore, the Monte Carlo simulation was used based on the infinite slope method for a cross-section profile obtained from 3 wells. The results show that the well located at the upper part of the slope (F 10.1) has a stability factor smaller that 1 (Fs = 0.83), even when water is not present in the penetrated geological formations, suggesting local landslide occurrence. However, a different situation appears for the other two wells, drilled on the middle (F 10.2) and at the base (F 10.3) of the slope. Here, the computations indicate stability (Fs = 4.16 and 2.42, respectively), even at complete flooding of the intercepted geological formations. The authors consider this situation to occur due to the fact that the sliding surface's angle for F10.2 and F10.3 is much smaller than for F 10.1. This conclusion is also confirmed by the results obtained using Monte Carlo simulation for the whole profile. The mean stability factor for this alignment indicates that, considering the present-day conditions, the slope does not slide. This simulation was made without taking into account the anthropic overloading of the slope with buildings. This factor may drastically alter the equilibrium within the slope and cause failure. [ABSTRACT FROM AUTHOR]