A Finite Difference Study on the Use of Inclined Micropiles for Slope Stability Analysis under Seismic LoadingSahar Ismail & Riad Al WardanyDepartment of Civil and Environmental Engineering, Rafik Hariri University,Mechref, LebanonFadi Hage ChehadeNumerical Center, Doctoral School of Science and Technology, IUT-Saida, Lebanese University, Beirut,Lebanon

ABSTRACTMicropiles have been used for slope stabilization and proven as an efficient solution since they are easily installed and they do not affect the equilibrium of the structure. Previous studies about micropiles and slope stability consider vertical or battered micropiles. Thus, a 2D Finite Difference parametric study using FLAC was carried out to study the effect of stabilizing a silty sandy slope under seismic loading by inclined micropiles. This paper consider the effects of micropiles' inclination angle, length, position along the inclined slope and number in static and dynamic conditions. The results are presented in terms of the slope factor of safety, horizontal displacement and amplification of the soil grains along the inclined surface of the slope at maximum loading. The results show that the factor of safety and the soil horizontal displacement depend on the micropile inclination angle, length, position and number. As the length of the micropile increases, the factor of safety increases while the horizontal displacement decreases. Moreover, as the inserted micropiles number increases, the permanent displacement along the inclined slope decreases significantly. From this study, it was found that the optimum stabilization solution can be reached by inserting 45° inclined micropiles at the middle of the slope.