Effect of inter-particle rolling resistance on passive earth pressure against a translating rigid retaining wall.

The presence of the inter-particle rolling resistance of soil grains results in higher bulk shear strength in the soil, which relates to the earth pressure calculation based on the classic theory. This paper focuses on the effect of the inter-particle rolling resistance on the earth pressure against a rigid retaining wall. A particle contact model considering the inter-particle rolling resistance was implemented into the distinct element code PFC2D, which was then used to simulate a rigid wall retaining a sandy backfill. The passive earth pressure against the wall subjected to a translational displacement was analyzed and compared with results without considering the inter-particle rolling resistance. The influence of the inter-particle rolling resistance was examined from the microscopic scale (e.g., averaged micro-pure rotation-rate) as well as the macroscopic scale (e.g., the magnitude and action point of resultant earth pressures). The results show that the inter-particle rolling resistance of the backfill strongly affects the value of passive thrust behind the wall, but it has no significant effect on the action position of the thrust. The distribution of micro-pure rotation-rate (APR) in the backfill provides an insight into the connection between inter-particle rolling resistance to the energy dissipation in the shear zone behind the wall. [ABSTRACT FROM AUTHOR]