Stability and Seismic Response Analysis of Geocell Reinforced Slopes based on an Equivalent Composite Approach

Abstract

Geocell-reinforced slopes have proven to be one of the most efficient techniques of slope stabilization. However, the efficacy of utilizing geocell layers as fascia or reinforcement in slopes against seismic loading is yet to be intricately ventured. In this paper, numerical plane-strain modelling of geocell-reinforced slopes is carried out to study their response against seismic loading. Both pseudostatic analysis and non-linear time-history analysis are carried out considering a chosen strong motion history. Equivalent Composite Approach (ECA) is employed in modelling the 3-dimensional geocell layer as an equivalent 2-dimensional soil-geocell composite by introducing improved strength and stiffness imparted by the geocells. The improved strength is obtained from the additional confining pressure induced by the geocell pocket boundaries. The improved stiffness of the soil-geocell composite is calculated from the stiffness of the unreinforced slope material and the tensile modulus of the geocell material. Three different configurations of the placement of geocell layers are implemented to evaluate the response, where the geocell layers are introduced in the form of fascia, reinforcement, or a combination of both. The global stability of the reinforced slope sections is analysed using pseudostatic seismic coefficients assessed through different techniques, while the acceleration response and deformation of the slope face are analysed using an acceleration-time history input. The influence of geocell layers on the hysteresis behaviour of the slope face and on the development of potential slip surfaces is also investigated to yield motion specific observations.