Steel box girder erection method applied to steel and concrete hybrid girder cable-stayed bridge

The invention discloses a steel box girder erection method which is applied to a steel and concrete hybrid girder cable-stayed bridge. Side-span concrete girders are constructed first, and middle-span steel box girders are installed in a segmented mode. The segments of the steel box girders are lifted to a girder transport cart on the constructed side-span girder face through a bridge tail girder lifting gantry, the steel box girders are transported into a cantilever bridge girder erection machine along rails on the girder face through the cart, and then the steel box girders are hoisted, transferred forward, turned, transferred backward and installed through the cantilever bridge girder erection machine. The constructed side-span concrete girders serve as the middle-span steel box girder transportation channel for transporting girders on girders, the steel box girder lifting, transporting and erecting process is not limited by ground construction, and navigation is not affected; the problems of construction environment constraints are solved, and multiple construction devices involved in steel box girder erection are innovatively designed, developed and successfully applied. According to on-site practice, all links are compact and controllable in terms of construction time, the steel box girder erection method is safe, reliable and high in applicability, the defects of a traditional construction method are compensated for, and development of the steel box girder erection construction technology is promoted.