Static And Stability Analysis Of Kunyang Bridge On Wenzhou-Fuzhou Railway

Kunyang Bridge on Wenzhou-Fuzhou Railway is a combined structure composed of prestressed concrete continuous box beam and concrete-filled steel tubular (CFST) arch. Based on the bridge under construction and the finite element theory, the calculating model for the bridge was built. This dissertation focuses on static analysis of the bridge in the main construction phases, a space-stress analysis for the connection area of the beam and arch with complicated structural stress, the influence of the main design parameters on the internal force and the stability. Specifically speaking, this dissertation has dealt with the following respects:1. The internal forces, stress and deformation throughout the construction process of Kunyang Bridge have been calculated by MIDAS software. Comparison and analysis are made between the results of the theory analysis and the measured datum in the construction control. It is demonstrated that the sectional stress of the main girder and the arch ribs can meet the requirements of the standards in each construction stage by erecting the continuous girder prior to that of the arches and using cantilever casting construction. The construction method is also proved to be reasonable.2. According to Saint-Venant principle, the finite element space model for the connection area of the beam and arch was built in order to simulate the stress characteristics by ANSYS software adopting the method of combining the plane bar structure analysis with three-dimensional finite element analysis. The stress of the connection area of the beam and arch are within a reasonable range with the exception of the stress concentration regions. The shape and the local structure of the arch abutment which have been adopted in this bridge design are basically a reasonable design scheme, which can ensure the function of the structural force and the force transferring.3. Among the design parameters of the continuous beam-arch composite bridge, the arch axis, the ratio of the rise to span and the stiffness ratic have more obvious influence on the structural internal force. Through changing some design parameters(arch axis, ratio of the rise to span, stiffness ratic), the influence to the internal force distribution of the continuous beam-arch composite bridge is compared under different design parameters. The optimal range of these parameters is pointed out and some advances are also given.4. The factors influencing buckling eigenvalues of the bridge, such as the number and the the type of the transverse brace, the arch rib obliquity etc., have been discussed. The results showed that the number and the the type of the transverse brace have great influence on the sability of the bridge and non-directional force of suspender can improve global stability about 10%, but the change of the arch rib obliquity has no obvious influence on the global stability.