Construction method of viaduct

According to the construction method of the viaduct, the steel box girders are spliced according to the preset size through construction in the transverse direction of the viaduct, then construction in the longitudinal direction of the viaduct is utilized, the spliced steel box girders are spliced to form all the sections forming the viaduct, and finally all the sections are spliced to form the complete viaduct. When construction in the longitudinal bridge direction is carried out, a site is leveled firstly, and a plurality of temporary supports are built at the positions adjacent to piers along the longitudinal bridge direction; hoisting the assembled steel box girders by utilizing hoisting equipment, and sequentially assembling the plurality of steel box girders to form sections with preset lengths; and finally, cantilever arm installation is conducted at the two ends of each section through hoisting equipment, and the cantilever arm between every two adjacent sections is welded, so that a complete viaduct