The invention relates to a variable cross-section
cantilever bridge
box girder self-locking synchronization pushing
system and a construction method. The variable cross-section
cantilever bridge
box girder self-locking synchronization pushing
system comprises a pushing sliding bridge
box girder welding assembling platform
system, sliding tracks, a group of sliding shoes and a group of self-locking synchronization pushing devices, wherein the group of sliding shoes and the group of self-locking synchronization pushing devices are installed on the sliding tracks, and pushing is automatically controlled. The variable cross-section
cantilever bridge box girder self-locking synchronization pushing system is characterized in that every self-locking synchronization pushing device comprises a hydraulic pushing oil cylinder and a self-locking pushing rail clamping device, adjusting pad blocks for adjusting
bridge type camber are arranged on the upper portions of the sliding shoes, and thrust plates and side limiting plates, which are used for preventing the sliding shoes from
jumping during pushing, are respectively arranged in front of and on the sides of the sliding shoes. Track limiting plates for limiting sliding shoe offset are arranged on two sides of the parts on the lower portions of the sliding shoes contacted with the tracks, a bridge box girder is placed on the upper portions of the sliding shoes, and a bridge box girder transition section and a guide beam are arranged at the front end of the first section of bridge box girder. By adopting the variable cross-section cantilever bridge box girder self-locking synchronization pushing
system construction method, the problem of difficulty in bridge erection in complex environments of crossing railways and the like is effectively solved, and the variable cross-section cantilever bridge box girder self-locking synchronization pushing system is safe, reliable and high in efficiency.