Cable-stayed bridge, as a cable system, has greater spanning capacity than beam bridge and is the most important bridge type in long-span bridges. Cable-stayed bridge is a deck suspended by many steel cables directly connected with towers. Cable-stayed bridge consists of pylon, main girder and stay cables. The types of cable towers are A-type, inverted Y-type, H-type and single-column type, and the materials are steel and concrete. Stay cables are arranged with single cable plane, parallel double cable plane and stay cable plane. The first modern cable-stayed bridge was built in Sweden in 1955 by German DEMAG company, with a main span of 182. The 6-meter-high Romson Bridge. At present, the longest span cable-stayed bridge in the world is Sutong Bridge in People's Republic of China (PRC) (China), with a main span of 65,438+0,088 meters, which was put into trial operation on April 2, 2008. Cable-stayed bridge is a kind of bridge with several cables tied to the tower column. It consists of three parts: beam, stay cable and tower column. Cable-stayed bridge is a self-anchored system. The horizontal force of the stay cable is borne by the cross beam, which is not only supported on the pier, but also supported on the stay cable led out from the tower column. According to the different materials used in the beam, it can be divided into steel cable-stayed bridge, composite beam cable-stayed bridge and concrete beam cable-stayed bridge.