Simulation of river ice jam formation

A three-dimensional discrete element ice model has been coupled with a one-dimensional unsteady channel flow model and used to simulate ice jam formation at an ice control structure. The ice control structure consisted of three cylindrical piers placed across a straight, rectangular channel. The discrete element model is capable of modeling the behavior of several thousand, three-dimensional disk-shaped flees by resolving the inter-flee contact forces, fluid drag force, gravitational force, and buoyancy force acting on each flee. The unsteady flow model is capable of modeling open water flow, flow under an ice jam, and high Reynolds number seepage flow through an ice jam. Two types of ice jams were simulated. The first began with a single layer of flees, evenly distributed on the water surface, moving downstream in a steady, uniform flow. The second began with the release of an upstream impoundment of flees carried downstream by the resulting surge of water. During each simulation the river stage, discharge, forces, and ice jam profiles were calculated at uniformly spaced cross-sections and time intervals.