Earthquake Resistant Design of Reinforced Soil Structures Using Pseudo Static Method

Problem statement: This study presented a method to evaluate the internal stability of reinforced soil structures against tension and pullout modes of failure using pseudo-static method for earthquake conditions. Approach: Using limit equilibrium method and assuming the failure surface to be logarithmic spiral, analysis was conducted to maintain internal stability against both tensile and pullout failure of the reinforcements. For the seismic conditions, factors of safety of all the geosynthetic layers in relation to tension and pullout failure modes were determined for different magnitudes of friction angle of backfill, horizontal seismic accelerations and surcharge load acting on the wall. Results: The efforts had been made to obtain the number of layers, pullout length and total length of the reinforcement at each layer level for the desired safety level against tension and pullout modes of failure. The influence of friction angle of the backfill, horizontal earthquake acceleration and surcharge load on number of layers, pullout length and total length of the reinforcement needed for the stability at each level was discussed. Conclusion/Recommendations: The developed method provided a closed form solution for the active earth pressure acting on the reinforced soil structures using rotational log-spiral failure mechanism under earthquake loading ensuring safety against tension and pullout modes of failure.