An analytical method for predicting load acting on geosynthetic overlying voids

Soil arching often occurs in geosynthetic-reinforced structures, where the underlying soil has voids, resulting in load transmission from the subsided area to surrounding less deformed area. A new method is proposed to predict load acting on gensynthetic overlying voids. The shape of soil arch and stress states of all the points at the soil arch can be obtained by combining nonlinear M-C yielding criterion, non-associated flow rule with static equilibrium of segmental arch through a dilatancy coefficient. The load applied to the geosynthetic can be determined by load transmission from the overlying soil, to the soil arch, and onto the collapsed soil. The model is verified using a model test conducted by Zhu et al. (2012), the soil pressure acting on the deflected geosynthetic is reasonably predicted. Due to the inherent nonlinear behaviour of soil, nonlinear failure criterion can better describe the stresses and deformations of the soil and geosynthetic. Soil nonlinearity has significant influence on the evaluation of arching effect. Ignoring the nonlinear behaviour of soil tends to underestimate the soil pressure acting on the geosynthetic. There exists an optimal subsidence width for which the soil pressure acting on the geosynthetic is minimal. The method used in this study is more appropriate where a large deflection occurs in the geosynthetic and provides a novel approach to evaluating soil arching under these conditions.