Influence of Structural Fill Properties on Reinforced Soil Movements in Helang Landslide, India

When a reinforced soil system is made of different types of reinforcements, those can be considered as composite soil reinforcement system. One of the proven systems is to use strong polymeric elements as primary reinforcement and steel wire mesh of moderate strength as secondary reinforcement. The deformation of such structures is highly influenced by structural fill characteristics in addition to factors like stiffness and spacing of reinforcements. A series of studies are conducted on a reinforced soil structure executed in a highly landslide prone area, Helang in mountainous terrain of Himalayas in Uttarakhand state, India. In the Himalayas, the native soil available for structural fill will be a mixture of highly varying gradations. Thus, screening of fill is essential while balancing cut and fill volumes. This paper explores variations of deformation of reinforced soil structure at Helang with respect to friction angle and unit weight of structural fill. The model is validated by instrumentation data and parametric study is supported by finite element and limit equilibrium analysis with varying values of friction angle and fill unit weight.