Abstract: In order to reveal flood damage rule, make clear the main causes of flood damage and improve the flood damage prevention and cure technical measures for highway-bridge binding site in a mountainous area, model tests were carried out under 3 working conditions, without prevention and cure measures, adding mortar rubble, and adding stone cage cofferdam to the site. The water flow velocity, the flood damage accumulations' thickness and the flood damage dig depth were measured. Relationships between the flood danmage scour time and the flood damage accumulations' thickness, dig depth and the water flow velocity were established. Research shows that under the working condition of without prevention and cure measures, the model is destroyed completely, the erosion and destruction progress step by step and with significant stages, and the flood damage accumulations' form is characterized by accumulations' thickness in vertical and horizontal direction, that under the working conditions of mortar rubble and stone cage cofferdam prevention and cure, the model tested is intact.

Key words: highway-bridge, mortar rubble, stone cage cofferdam, model test, highway-birdge binding site, flood damage