Overall slope stability of prestressed geosynthetic-reinforced embankments on soft ground

This Technical Note presents the derivation of an expression for the factor of safety with respect to the overall slope stability of a prestressed geosynthetic-reinforced embankment resting on soft ground. A detailed parametric study is carried out to observe the effect on the factor of safety of prestressing the geosynthetic reinforcement. It is found that prestressing the geosynthetic reinforcement is more beneficial for soft ground than stiff ground when the foundation soil is much more shallow than the height of the embankment. If the mobilised tensile force is lower than the required value for overall slope stability, which is typical at the end of embankment construction, prestressing the geosynthetic proves to be effective in providing overall slope stability. Relatively steep side slopes of embankments can be provided by prestressing the geosynthetic reinforcement. The beneficial effect of prestressing is more significant for cohesionless embankment soil than for cohesive soil.