BEHAVIOR OF TIANXINGZHOU YANGTZE BRIDGE OF WUGUANG PASSENGER DEDICATED LINE

摘要

The newly completed Wuhan Tianxingzhou Changjiang Bridge is a key project of the Passenger Dedicated Line from Wuhan to Guangzhou. It is a cable stayed bridge with two towers, three cable planes and three trusses, and its spans are arranged as 98+196+504+196+98 m. The bridge has two layers, the upper is six carriageways, and the lower is four line railways. The ballast railway floor system consists of steel stringers, crossbeams and concrete slab which composite only with the steel stringers. In this paper the main structure system, the modifying of the railway floor system and the behaviour of the bridge is introduced and studied. The design of the railway floor system was quite difficult and experienced a hard process and changed several times. The key problem is how to conforming the deformations and stress levels of the lower chords, the stringers, the crossbeams and the concrete slab. The prime plan of the railway floor system did not arranger expansion stringer or every six panel arrange one expansion stringer. FEM results showed that this plan was not available. The main problem was that the stresses of the crossbeams caused by horizontal bending were too large. Then the ideas of arranging braking bracings or arranging more expansion stringers were proposed. The former could reduce the stresses of crossbeams effectively, but the stresses of the stringers increased obviously and became a governing factor of design. At last the plan of arranging one expansion stringer every two panels was finally used and good effect was obtained. The stiffness and strength is sufficient and the behaviour of the bridge is properly.