Impact Behavior of a Laterally Loaded Guardrail Post near Slopes by Hybrid SPH Model

Abstract

Based on the assumption that guardrail systems are placed in soil with horizontal ground, interaction behavior between soil and a post has been presented using some relevant theories such as the theory of subgrade reaction, Winkler’s spring theory, and the nonlinearp-ycurve method. However, they can be constructed on cut slopes or compacted sloping embankments beside the roadway. Thus, the theory based on the conventional discrete spring models cannot be directly applied to the sloping ground since the ground inclination significantly affects the ultimate soil resistance. In this study, two approaches for comparison of them are adopted to present the interaction behavior between soil and the post. One of them is the three-dimensional Lagrangian approach, and the other is the hybrid approach that combines the finite elements and the particles based on SPH (smoothed particle hydrodynamics) modeling. The SPH method is expected to overcome drawbacks of large mesh distortion in soil regions consisting of node-connected finite elements due to lateral movement of the guardrail post. The soil-post interaction in the sloping ground under conditions of quasi-static and dynamic loads is investigated according to ground inclination, embedment length, and embedment location of the post near the slope.