Displacement-based internal design of geosynthetic-reinforced earth structures subjected to seismic loading conditions Available to Purchase

A majority of the existing analytical approaches for displacement-based seismic design of geosynthetic-reinforced earth structures (GRESs) have been developed by considering only a translational mode of failure (external sliding stability), and consequently do not provide a means for assessing the seismic displacement of GRESs due to rotational movements (internal stability). Internal rotational failure can degenerate to a translational one should it be more critical; however, the reverse is not true, which makes rotational failure a more generic mechanism. To address this issue, this paper presents a new analytical–numerical framework for the displacement-based design of GRESs, which assesses the potential for earthquake-induced displacements via an internal stability (rotational) failure mechanism. For design purposes, in order to determine the superimposed force in the reinforcement due to seismicity and its associated displacement, the proposed approach examines two limiting conditions: (a) the upper-bound force that can be mobilised in the reinforcement, as determined by pseudo-static limit equilibrium; and (b) the force that can be induced in the reinforcement by a given earthquake acceleration applied over a finite time increment. Either condition satisfies equilibrium. The prevailing seismically induced force and displacement in the reinforcement for each time increment are determined by selecting the smaller value that results from these two conditions. As an auxiliary tool, a set of pullout simulations was performed using finite-element analysis in order to relate the force and displacement in the geosynthetic reinforcement for various geosynthetic stiffnesses. To illustrate the application of the proposed method, a design example using a Kobe earthquake record is presented. For this example, the superimposed force in the reinforcement due to seismicity, the seismic displacement, and the seismic rotation are calculated. The required unfactored geosynthetic strength is then determined using a uniform distribution function.