Viaduct bottom post-collision protection device

The invention relates to the technical field of viaduct protection, and discloses a viaduct bottom post-collision protection device. The device includes a bridge, a damping apparatus is fixedly mounted at the bottom of the bridge, pulleys are movably connected to two sides of the damping apparatus and located at the bottom of the bridge. Crawler belts are movably connected to the surfaces of the pulleys, a buffer apparatus is fixedly mounted in the bridge, sliding grooves are formed on two side inner walls in the bridge, when a vehicle collides with a viaduct bottom under a special condition,the vehicle top contacts the viaduct bottom, under the action of a spring in the damping apparatus, the crawler belts make contact with the vehicle top and move, at the moment, the vehicle can apply an upward force to the viaduct bottom due to the height of the vehicle itself, the crawler belts can be jacked up, a corrugated pipe in the buffer apparatus is compressed by a certain stroke, the vehicle top and the crawler be