Analysis On Composite Structure System Bridge With Special-Shaped Arch And Continuous Rigid Frame

Beam-arch composite system bridge has become a competitive bridge type in modern bridge design because of its rational structural stress distribution, diversity of construction methods and beautiful appearance. This paper focuses on Xiushui Bridge, a newly built bridge with special-shaped arch and prestressed concrete continuous rigid frame, to assess its rationality of force distribution and optimize the tension force of suspension cables under the bridge-finished status. The local model to beam-arch joint has been built based on above analysis to provide suggestions for optimizing the local design. The main contents in this paper are as follows:(1) A brief introduction to the characteristics and classification of beam-arch composite bridge as well as the current research on beam-arch composite system bridge both in China and abroad are given in the paper.(2) A overall space model of Xiushui Bridge has been built by using the finite element software Midas/Civil to analysis the ultimate limit state, serviceability limit state as well as the stability of arch. It is concluded that the structure design is reasonable and has a certain safety margin.(3) The local analysis model to beam-arch joint has been established by using the finite element software Midas/Fea to analysis the stress peak and weak areas. It is concluded that the principal tensile stress and principal compressive stress of most areas in beam-arch joint are within permissible values. But there are still some stress concentrations in certain areas.(4) The unknown load factor method in Midas/Civil has been used to optimize the rational forces in suspension cables under dead load with the aids of controlling the moment in rigid frame beam.