Reinforcement strength and length requirement of each layer in a nailed slope subjected to seismic loading

Abstract

ABSTRACT Estimating support force and length requirement of each reinforcement layer based on limit equilibrium framework remains a statically indeterminate problem and consideration of seismic loading further increases its complexity. The present study addresses it by proposing a novel calculus-based methodology based upon the modified pseudo-dynamic approach to analyse the internal stability of nailed slopes. The effects of slope angle, shear strength parameters of soil, motion parameters, nail orientation, and surcharge were discussed. Though the deeper nail layers are observed to require more support forces, their active zone nail length requirement is lesser. This trend combined with the higher nail-soil bond strengths due to higher vertical stresses suggests that the bottommost nail layer need not be the longest. Both possible directions of initial vertical acceleration must be considered with and without surcharge for designs to arrive at the largest length requirement of each nail layer. The closed-form solutions presented herein to estimate layer-wise strength and length requirement would benefit nailed slope design practitioners.