Infiltration into an embankment reinforced by nonwoven geotextiles

Abstract

The hydraulic behaviour of permeable geosynthetics within unsaturated embankments subjected to infiltration is examined using the finite element method. The van Genuchten – Mualem model is employed to evaluate unsaturated hydraulic characteristics for both the soil and nonwoven geotextile. Using pore-water pressures obtained from the finite element analysis, stability analyses are conducted for the embankments, and the contribution of the nonwoven geo textile to stability is evaluated with reference to the observed performance of instrumented embankments. A numerical study is also conducted to examine the effect of geotextile configuration on the performance of reinforced embankments subject to infiltration. This study shows that nonwoven geotextiles may retard water flow in situations where the pore pressure is negative, whereas they act as a drainage material in situations where pore pressures are positive. It is also shown that the contribution of the nonwoven geotextile to the stability of the embankment as a drainage material is much less substantial than its role as a reinforcing material.Key words: nonwoven geotextile, drainage, unsaturated, embankment, stability.