A Case Study on Comparative Study of Reinforced Soil Wall and Soil Nailed Wall

Abstract

Reinforced Soil walls and Soil nailed walls are the major types of Earth Retaining Structures vigorously used in India, in recent times, owing to their enhanced performance and simplicity. Even though their purpose of construction is the same, that is, to support high embankments, the choice of type of protection plays a vital role in overall efficiency of the project. Hence, selection of wall type is of high significance. To decide the type of wall, parameters like, soil type, geological formation, index and engineering properties of the soil, drainage condition, geometry of angle etc., are taken into consideration. In this project, an attempt has been done to study an area where a high embankment is needed to accommodate a National Highway over it. Initially, a Reinforced soil wall is designed for the nearly vertical slopes on either side of the Highway. But due to terrain constraints and soil unavailability, the design has been changed to Soil Nail wall. A detailed comparative study between the designs is done to select the most efficient one. Field pull-out tests are carried out at site to calculate bond strength available in the soil. Excel spread sheets for design using Two part wedge mechanism are made use of, to estimate the global factor of safety. These values are comparted with those factors of safety obtained from simulating the same design layout in Geo5 software. The results are compared and the reliability of this method over software designs is evaluated.