Tongji Bridge in Guigang City, Guangxi Province, as a part of Tongji Avenue, crosses the Yujiang River. Dafang Company provided the jacking equipment and steel box girder jacking technical services.
The bridge is a self-anchored suspension bridge with a span of 50m+140m+280m+140m+50m and a total length of 660m; The beam body is located on a circular curve with a radius of 5000 m (road crown) and a 2.35% longitudinal slope.
The total length of the steel box girder of the main bridge is 518m. The top surface of the steel box is 39m wide, presenting a closed box section. Sidewalks are cantilevered on both sides. The bottom flat bottom plate is 30.9m wide, and the cantilevered arm plates on both sides are 5.2m wide. Height of beam at bridge centerline 3.5m. The horizontal spacing between the two slings on the steel beam is 36.5m, and the longitudinal spacing is 6.0m. The standard section length of the steel beam is 9.0m. The whole bridge is divided into 61 steel box sections, and the total weight is 11000t.
The construction method of girder first and then cable is adopted for the main girder. The pushing site is arranged on the south bank of Yujiang River, and the pushing construction is conducted from south to north. The north bank is closed first and then the south bank is closed. Based on the construction characteristics of self-anchored suspension bridge from erecting beam to pulling cable, the method of “multi point continuous pushing in the same direction by sections” is adopted for the installation of steel beam, with the maximum weight of 11000t.