Seismic Stability Analysis of Road Embankment Resting on Geotextile Reinforced Soft Soil

Slope failures induced by seismic activity are critical issues related to geotechnical earthquake hazards thereby damaging various transportation corridors such as road embankments, highways and dams. This paper discusses slope stability of a 8 m high road embankment resting on soft soil under saturated conditions under the action of seismic activity analogous to 0.38 g acceleration caused in seismic zone IV using equivalent linear dynamic model in Quake/W and Slope/W. Unreinforced road embankment and soft soil resulted in poor factor of safety of 1.138 and subsequently large displacements and accelerations thereby causing the simulations to be unstable. Further, the prevalence of saturated conditions yielded liquefaction zone underneath the road embankment which holds the potential of intensifying the destruction and complete collapse of the structure. Since the simulation yielded low factor of safety, layers of geotextile were applied based on the susceptible liquefaction zone. The reinforcement enhanced the stability in terms of total and vertical displacements, q/p′ ratio, induced accelerations. In addition, effect on total stress and excess pore-water pressures were also analyzed. Geotextiles proved to be effective in stabilizing the concerned simulation yielding factor of 2.813 and 1.793 for pre- and post-earthquake events and declining displacements and acceleration by 33.3% and hence proved to be an effective reinforcement in minimizing seismic-induced dynamic forces and enhancing the overall seismic performance of the simulation model. This research can be useful in rectifying stability-related issues with similar geotechnical and prevailing seismic conditions.