Construction method for synchronously jacking whole bridge to replace support

The invention provides a construction method for synchronously jacking the whole bridge to replace a support, and belongs to the field of municipal construction. The construction method comprises thefollowing steps that S1, preparation work is carried out before jacking; S2, jacking preparation is carried out; S3, trial jacking is carried out; S4, a main beam is jacked synchronously; and S5, thesupport is replaced. Temporary supporting is conducted so that the old support is withdrawn, a leveling steel plate is additionally arranged, and the beam is fallen down; after the leveling steel plate and the new support are installed, beam falling and reset operation can be conducted, all jacks are subjected to oil returning and beam falling synchronously, the beam body needs to be kept overallbalanced in the beam falling process, and synchronous overall beam falling is conducted according to the jacking inverse process and in a graded mode till the beam body is completely fallen. Accordingto the construction method,