Copyright to IJIRSET www.ijirset.com 25 ISSN (Online) : 2319 - 8753 ISSN (Print) : 2347 - 6710 International Journal of Innovative Research in Science, Engineering and Technology An ISO 3297: 2007 Certified Organization, Volume 2, Special Issue 1, December 2013 Proceedings of International Conference on Energy and Environment-2013 (ICEE 2013) On 12 th to 14 th December Organized by Department of Civil Engineering and Mechanical Engineering of Rajiv Gandhi Institute of Technology, Kottayam, Kerala, India INTERFACIAL FRICTION PROPERTIES OF GEOCELL REINFORCED SAND Manju G S, Gali Madhavi Latha Research Scholar, Indian Institute of Science, Bangalore, Karnataka, 560012, India Associate Professor, Indian Institute of Science, Bangalore, Karnataka, 560012 India ABSTRACT Modified direct shear tests were carried out to investigate the interface shear properties of sand-geocell interfaces. Two different geonets with high contrast in tensile strength properties and aperture size were used to fabricate geocells. Geocells were fabricated using geonets by hand stitching in case of weaker geonet and by connecting with steel wire in case of stronger geonet. Effects of geocell pocket size on the interface shear properties was investigated for both types of geocells. Three different geocell arrangements of cell diameter 150mm, 100mm and 75mm were used in the tests. Results showed that sand-geocell interfaces showed adhesion unlike the sand alone interface, which only exhibited interfacial friction. It was observed that the tensile stiffness of geocell material plays significant role in governing the interface friction characteristics of geocell reinforced sand, apart from the pocket size of cells. Keywords: Interface, Geocell, Geonet, Reinforced sand, friction angle. 1. INTRODUCTION Use of geosynthetics as reinforcement in soils for mproving the performance of retaining walls, foundations and slopes etc. has received considerable attention. Any geosynthetic material employed as reinforcement has the main task of resisting applied stresses or preventing unacceptable deformations in reinforced soil structures. Soil-geosynthetic interaction parameters play important role for design and performance of reinforced soil structures. In general, cohesionless soils are preferred as backfill or neighboring soil to the reinforcement for better performance. Geocells are three dimensional cellular network of geosynthetic material, fabricated from geogrids or custom made by ultrasonic welding of polymeric sheets. These are filled with sand or aggregate and extensively used for soil reinforcement in retaining walls, embankments and roads. Several researchers tried to investigate the beneficial effects of geocell reinforced soils (e.g. Bathurst and Karpurapu, 1993; Rajagopal et al. 1999; Latha et al., 2000). Interfacial friction properties of geocells are very important to design these structures because slight variation in the adhesion or friction properties at the interface will have considerable effect on the overall performance of the structure because the additional stability of strength to the structures imparted by geosynthetic reinforcement is governed by the pullout and shear resistance offered by the geocell confined soil. Studies available on interfacial friction properties of geosynthetic reinforced soils are many