Engineers Australia

Application of high strength woven geotextile in embankment stability control on soft soils

B. Wai-Choo Kok, J. Berends and K. Hooi Loke

Abstract

In a fast paced construction world, the application of high strength woven geotextile as tensioned membranes to restrict the vertical displacement of ground underneath and subsequently increase the stability of road embankments is becoming more popular. Due to the relatively low permeability of soft soils, particularly clayey materials, the drainage and consolidation process is significantly slow. Road embankments need reinforcement in order to increase the soil shearing resistance before they are able to support their own weight. The main objective of this study is to quantify the effectiveness of high strength woven geotextile in stability control on soft soils in the Kedron Brook floodplain area, Brisbane. This area consists mainly of Holocene Clays up to 26 m depth. More than 1,000,000 m2 of high strength woven geotextile has been used as reinforcement to control stability in heavily instrumented road embankments located in the Airport Interchange area of Brisbane, Australia. Lateral ground movement due to the consolidation process by fill activity was computed using 2D finite element analysis and compared to the horizontal displacement recorded by inclinometers installed along the embankments and quantified as settlement ratio. The settlement ratio ranges from 1.2 to 4.0 in reinforced embankments and 0.2 to 2.7 in unreinforced embankments. The effectiveness of high strength woven geotextile increased the settlement ratio and provided an increased safety factor in stability control of road embankments on soft soil areas to enable an improved construction rate.