Construction Technology Study Of 32+128+32m Rigid Frame Tied-arch Bridge

The construction technique about the rigid frame tied arch bridge is studied in this paper,which is based on the project of nanchang-jiujiang Intercity Railway Yongxiu large bridge with main span of 32+128+32m.The structural system for the bridge is the rigid frame arch bridge.The bridge arch and pier are consolidate and the pier are separate from main beam.The arch are the main force to play bearing function.The main beam pass the load by the boom and then the arch foot transfer force to the foundation.The construction scheme of Yongxiu main bridge is beam first and arch after,and then the bridge.Deep water foundation use the pile construction in the water platform and use the steel sheet pile cofferdam to the cap construction.Cast in place beam supports a bored pile foundation,single pile single column beam connection with beam force transmission parts.Cast-in-place use segmental construction before integral tension.After the tension on the beam,arch brackets are erected and the arch are hoisted with floating cranes,welded into the bridge.The following are the main work and conclusions:(1)a detailed description of the natural condition of the engineering,technical design standards,main projects and quantity,and the overall difficulties.(2)The design and check calculation about the steel sheet pile cofferdam of the foundation construction.It is found that during excavation,the maximum of bending moment,shear force and displacement occurs in different conditions.And it is described that the temperature control measures cap,construction program and concrete pier itself.(3)The construction scheme and checking about the upper structure of the rigid frame tied arch bridge.The paper introduces the construction scheme,the construction process and prestressed control of the arch portion;the design and inspecting calculation of the assembled ribs stent;the determination of the installation order of the rib.It is found that in the rib installation process,a single rib collapsed and two downstream collapsed are two most unfavorable conditions,and the maximum tensile stress occurs in the I-beam beam pad.The installation process is influenced by wind loads.Therefore,when wind speed's effect is great,it should not be rib erection and welding operations.(4)The quality control,safety control and schedule control,combined with engineering.