Abstract: Dyke breach develops rapidly, and is hard to predict and to be dealt with. Current methods of dealing with breach emergency are mainly mechanized operation and throwing materials. However, in the development of the breach, the materials are prone to be washed away due to large water head difference at the entrance and high velocity of the flow. The breach, therefore, can only be blocked after the water flow slows down, which reduces the timeliness of emergency rescue and causes great economic loss after a long time of flood inflow. We invented a flow deceleration structure based on the principle of hydraulic energy dissipation to address the problem of breach closure under high speed flow. We expounded the basic principle of flow deceleration, and verified its deceleration effect and mechanical performance via model test and numerical simulation. By using this flow deceleration method, we can reduce the difficulty of emergency rescue and make it possible to close the breach at high flow velocity.

Key words: dyke burst, hydraulic energy dissipation, flow deceleration structure, flow deceleration method, closure of dyke burst