Abstract
Particles with large variety of sizes and shapes are seen in gravel-bed rivers. However the effect of collision between different size particles on motion of particles and bed structure are hardly clarified. This paper presents the result of the movable bed experiment with the numerical movable-bed channel which simulates three-dimensional motion of flow and particles of different sizes and shapes. The result of the numerical experiment revealed the characteristic difference in direction of contact forces of different size particles and the effect of particle volume concentration on the collisions. This paper shows that characteristics of collisions between different size particles strongly affect the motion of particles and bed structures.
