Lateral deformation characteristics of coir geomat reinforced vertical embankments

Abstract

For the design of internally stabilised reinforced earth walls, the lateral deformation is not considered as a design criterion and therefore, the designer would not know the performance of the wall with regard to its aesthetic appearance during its service life. Therefore, it is imperative that the designer limits the lateral deformation of reinforced earth walls under service loads. In addition to the durability considerations, suitability of application of coir geomats as the reinforcing material in a vertical embankment requires an investigation of its lateral deformation characteristics as well. In this study, the lateral deformation characteristics of a model vertical embankment (500 mm high, 700 mm long) reinforced with coir geomats of length 605 mm placed at a vertical spacing of 100 mm are compared with the lateral deformation characteristics of the same model embankment reinforced with needle punched geotextiles. The loading was carried out up to a maximum surcharge pressure of 250 kPa under natural moisture content and soaked conditions. The results show that the lateral deformation exhibited by the coir geomat reinforced embankment is comparatively less than that exhibited by the geotextile reinforced embankment corresponding to the same fraction of the design surcharge pressure which would develop the maximum tensile strength of the reinforcement, under the natural and soaked moisture conditions.