Nonlinear analysis of a geocell mattress on an elastic–plastic foundation

Geocell mattresses are widely used in soil reinforcement due to their three-dimensional configuration, which can effectively confine and reinforce soil filled in their pockets. However, design of geocell mattresses has not been well described in the literature. In this paper, a decoupled iterative method is presented to assess the behavior of a geocell mattress subjected to symmetric loads by modeling the mattress as a geometrically nonlinear beam resting on a nonlinear foundation. The nonlinearity of the foundation soil is represented by an elastic-perfectly plastic model. The tensionless nature of the soil is also taken into account in the model. Classical Winkler foundation beam theory is extended to solve the geocell reinforcement problem, with consideration of the lateral interfacial shearing resistance at the top and bottom of the beam. This resistance is assumed to be linearly proportional to the relative lateral displacement of the beam. The solution presented in this paper is verified by comparison with the two other existing published solutions for this problem. The effects of the two nonlinear parameters, i.e., the soil yield displacement and the beam geometric nonlinearity coefficient, on the deflection and tensile force within the beam are discussed. The results indicate that both the nonlinearity of the subgrade soil and the geometric nonlinearity of the beam significantly affect the beam’s response, especially when the beam undergoes a large deflection.