The invention relates to the technical field of bridge removing
engineering, and particularly relates to an integral lowering and removing
system of span box girders based on
bridge deck support and a construction method of the integral lowering and removing
system. The
system comprises piers which are used for lowering the two ends of a
box girder, and two sets of
cantilever reaction systems which are symmetrically arranged on the two ends of the lowered
box girder. Each
cantilever reaction system comprises two main outriggers and a hoisting cable. The ends of the two main outriggers are anchored on the corresponding
pier, and the other ends are spaced by a certain distance; the hoisting cable is slidingly connected to the end parts of the main outriggers, one end of the hoisting cable is connected with a lowering power system, and the other end of the hoisting cable is connected with a hoisting device which is used for hoisting the lowered
box girder. The lowering power system is installed on the main outriggers. According to the integral lowering and removing system, the box girders are lifted and lowered through continuous jacks of which hoisting capacities are large, so that the
cutting area of concrete is greatly reduced, and removing cost is effectively reduced; the invention has the characteristics such as good safety,
controllability,
operability and application prospect, and is not only suitable for removing the straight girder bridges, but also suitable for removing the curved bridges.