Integral dismantling construction method for half-span cantilever beam of river-crossing concrete continuous beam bridge

The invention relates to an integral dismantling construction method for a half-span cantilever beam of a river-crossing concrete continuous beam bridge, which comprises the following steps of: erecting a bracket on two barges, injecting ballast water into a cabin, enabling the height of the bracket to be lower than that of a beam bottom, respectively driving the two barges to the lower parts of outer side cantilever beams of two side spans of the bridge, anchoring and fixing, discharging part of water in the barges, and carrying out integral dismantling construction on the half-span cantilever beam of the river-crossing concrete continuous beam bridge. The barge is lifted, and the support abuts against the beam bottom; a closure section between the two cantilever beams of the side span is cut off, then the barge continues to drain water and rise, and the cantilever beams on the outer side of the side span are supported to a designated place in a floating mode; a closure section of the two cantilever beams of