The Ultimate Bearing Capacity Analysis And Research Of Beam-Arch Composite Rigid Frame Bridge

The beam-arch combination rigid frame bridge is a new type of composite bridge type improved in the form of conventional continuous rigid frame bridge and open-web continuous rigid frame bridge.The main idea is to hollow out the web of the box girder root and the main box root beam section It is divided into upper and lower limbs,so that the upper main beam tends to be stressed by the beam structure,and the lower main beam tends to be subjected to the arch structure to improve the bearing efficiency.The bridge type is beautiful in appearance and light in structure.It not only has the advantages of arch bridge and beam bridge,but also can overcome the problem of lower deflection and cracking of conventional continuous rigid frame bridge,and shorten the force span of box girder outside the fasting section and strengthen the bridge.The ability to leap.However,due to the influence of the main chord main beam,the lower chord main beam is subjected to part of the bending moment,which belongs to the compression and bending force member,and is subjected to large force and is easily damaged.Therefore,in order to further understand the bearing capacity of the beam-arch combination rigid frame bridge under specific loads,and accurately understand its failure mode and failure characteristics,the nonlinear static elastoplastic analysis method is used to carry out the beam-arch combination rigid frame bridge in the construction stage.The ultimate bearing capacity analysis of the whole process of the operation of the bridge has important practical and theoretical significance.Based on the background of the Lijiajialing River Bridge,this paper has carried out the following researches:Firstly,by summarizing the latest research status of inductive load capacity analysis,a method suitable for analyzing and studying the ultimate bearing capacity of new reinforced concrete bridge structures such as beam-arch combination rigid frame bridges is adopted,namely nonlinear static elastoplastic analysis method.Secondly,based on the nonlinear static elastoplastic analysis method,the ultimate bearing capacity of the whole process of the beam-arch composite rigid frame bridge of the world's largest span and the operation stage of the bridge is analyzed,and the beam-arch combination rigid frame bridge is obtained.The damage form of the new bridge type and its damage characteristics.Then,combined with the engineering example,the influence of structural designparameters such as concrete strength grade,side mid-span ratio,cross-sectional fasting rate and stiffness ratio of upper and lower chords on the ultimate bearing capacity of the beam-arch combination rigid frame bridge is studied by parameter analysis method.Finally,for the failure mode and its failure characteristics of the new bridge type such as the beam-arch combination rigid frame bridge,some reference value is given to ensure the construction safety,strengthen the local bars and improve the ultimate bearing capacity of the beam-arch combination rigid frame bridge.Value advice.