倾斜推移体激发颗粒流的连续介质模型

A Continuum Model of Granular Flow Induced By Inclined Plane

岩土工程中的土方推移等属于颗粒体的倾斜推移问题,探索了倾斜推移体在颗粒中平动推移时所受的阻力和升力。应用惯性数的理念,确定了流态类型,提出了适合非准静态流的广义摩擦系数。在此基础上,用基于改进的库伦被动土压力理论,通过基于二维颗粒离散元的位移场分析,建立了预测推移阻力和升力的楔体模型。结果表明,在其他条件相同时,推移阻力不随推移体的倾角变化,但是升力随倾角的增大而显著减小。升力和阻力分别是作用在推移体上合力的竖直分量和水平分量,且阻力和升力的比值为推移体倾角的正切值。广义摩擦角是推移速度和倾角的二次函数。所建立的模型可以预测不同倾角和推移速度时推移阻力和升力的大小。

Soils moving is one of the geotechnical problems,which can be described as a granular flow induced by inclined plane. This work aims to investigate the drag and lift forces acting on the inclined intruder. By using the inertial number concept to confirm the flow regime,a parameter named dynamic friction coefficient is induced to this non-quasi-static flow. By improving the Coulomb model,the displacement field is obtained by two dimensional discrete element method,and the wedge model for drag and lift forces is built. The results show that drag force is dependent of the inclined angle when the other conditions are the same,but the lift force is decreasing with the inclined angle. Drag and lift forces are the horizontal and vertical components of the total force,respectively. And the ratio of drag and lift forces is just equal to the tangent value of the inclined angle. The dynamic friction angle is the quadratic function of velocity and inclined angle. This model can predict different case in different inclined angle and velocity.