Arching effect on lateral pressure of confined granular material: numerical and theoretical analysis

摘要

Owing to the arching effect caused by stress transfer, the lateral pressure of confined granular material will be influenced by both the wall movement and the confined material width. In this paper, the lateral pressure of confined granular material is studied through the numerical and theoretical analysis. Discrete element-based numerical simulations of different widths are conducted to model the transition of the resultant lateral force. Based on numerical results, an analytical model for estimating the lateral pressure at limit state is proposed by the use of the horizontal slice element method. Moreover, the mobilization models of the granule-wall interface friction angle and the internal friction angle of the granular material are introduced to yield the lateral pressure at nonlimit state. Both numerical and theoretical results indicate that the transition of the lateral pressure can be divided into two stages based on the magnitudes of wall movements, at which the interface friction angle and internal friction angle are fully mobilized. For models with smaller width, the pressure decreases more rapidly in the first stage and eventually reaches smaller lateral pressure at active state, because the vertical stress of the material is transferred to the walls and the stress in the material is redistributed due to the superimposition of the arching effects.