Development and validation of deformation-dependent theoretical model for soil arching effect under unloading

Abstract

The evolution of soil arching effect is highly dependent on the variation of the unloading displacement or the soil differential displacement, while this issue has scarcely been addressed in a theoretical manner. In this study, a series of trapdoor tests were conducted on dry sand at various fill heights and relative densities. The testing results indicated that the evolution of soil arching effect followed the variation of shear bands closely. Based on the trapdoor testing results, a deformation-dependent theoretical model for soil arching effect was proposed under plane-strain condition. From the validation between the calculating results by the present theoretical model and the testing/simulating data from the present/previous studies, the present model succeeded to evaluate the evolution of the soil arching effect with the normalized trapdoor displacement. In addition, this model was validated to appropriately capture the characteristics of the soil arching effect, including the minimum/ultimate soil arching ratio and their corresponding normalized trapdoor displacements. Finally, a parametric study was performed on the present theoretical model, to assess the effects of fill height, trapdoor width, critical-state internal friction angle and initial relative density of soil on the soil arching effect, offering a technical reference for wider applications.