Comparative study of various flexible facing materials for soil nailed slopes

Abstract

As the natural slopes along the roadsides and embankments are not stable due to sliding or collapse, a technique termed “soil nailing” is used to stabilize the natural or man-made slopes. A small scale physical model of soil nailed slope in well-graded sandy soil and inclined at 60° to the horizontal using four number of soil nails is prepared in the laboratory using different flexible materials as flexible facing namely Uniaxial Geogrid, Geotextile fabric, Coir mat, Fine Stainless steel woven wire mesh. The results of these soil nailed slopes with flexible facing materials and the soil nailed slopes with no additional facing are compared. The behavior of these soil nailed slopes is analyzed by applying extra surcharge with the help of a hydraulic jack for load application on the physical model. The strain produced in the inserted soil nails on stress application is determined using a multimeter with the help of the sensors bonded to the each soil nail. Also, the deflection of the soil mass in horizontal and vertical deflection is measured as it is clearly visible from the perplex sheet provided on the outline of the physical model. The stress, horizontal displacement and vertical displacement induced in all the materials is measured and compared. The fine stainless steel wire mesh took the maximum stress of 1.23 N/mm2 with minimum displacements and minimum strength of 0.492 N/mm2 was possessed by the slope without any facing material. Also, the other flexible materials like uniaxial Geogrid and coir mat possessed good strength and hence can be an effective alternate to strengthen existing or new slopes and provision of flexible facing materials in soil nailing technique further aids in slope stabilization.