The Key Construction Technology Of Main Bridge’s Constructiontion Plan Of Zheng Jiao Intercity Railway Yellow River Bridge

The Zhengjiao Yellow River Bridge is a large four-line bridge built as part of the intercity railway from Zhengzhou to Jiaozuo,also part of the Beijing-Guangzhou railway. Its upper structure is three chord song under the deck Continuous Steel Truss. This structure form is the first time adapted to a bridge in China, and it is also the narrowest three- truss bride with four lines in our country. It is arranged by one joint and 2*200 meters holes, and each single unit of steel beam weighs about 7000 tonsThe incremental Launching contains three main trusses, single joint with two holes, no guide girder and two-way big boom spans, first used in the world. Many advanced technologies are first applied in this bridge around the world, such as rear-mounted, large tonnage jack single point level, long distance Incremental Launching. It is difficult to control in technology for horizontal rear Incremental Launching system, vertical landing systems, transverse correction system, precise position control technology. It requires very strict standard in intensity,rigidity and flatness of the pushing slide and the slider. Precise control of each process is very difficult, and the risk of security is very high.This paper introduces a research on construction program of the main bridge,based on the structural features of Zhengjiao Yellow River Bridge. There are many construction programs which have been researched and applied successfully:(1)Main span of 67 #, 79 #- 89 # piers are beach pier, directly in the pile foundation construction on the beach. Water 67 # pier- 75 # piers are in river channel shallow water area, built artificial island in the winter season, then pile foundation construction on the island. 76 # pier ~ 78 # piers are located in the main channel, drilling platform shall be built respectively applied drilling method for pile foundation construction.(2)The main bridge pier cap in 68#-78# steel sheet pile cofferdam construction method; North beach pier cap of 79#,84#-85# near the Yellow River and Qinhe, steel sheet pile cofferdam construction method. 67#, 80#, 81#, 86#-89# pier caps using the method of open excavation method to assist in the construction of precipitation method(3)The main bridge pier is solid pier, two times pouring completed by whole small truss rod less steel formwork technology.(4)According to the actual situation of the bridge pier location, steel truss girder bridge used three main trusses and double span, single beam, two-way large cantilever hole jacking construction technology, to ensure the rapid and high quality steel, steel girder erection construction completed on schedule.(5)79#-89# piers are located in the flat beach, first install gantry crane track,and then using two 65 t gantry crane suspension construction method of suspension assembly to complete the installation of the steel girders from the middle to both sides.