Application Research On Composite Trussed Continuous Beam Bridge With The Section Of Triple Concrete-filled Rectangular Steel Tubes

With the rapid development of our civil traffic project,it’s urgent to meet the demand of long span and heavy load bridge structure form. As a new type of composite structure form, concrete-filled rectangular steel tube of the composite structures has certain advantages in the aspect of economic indicators and the seismic performance,so it has wide prospect of application. Based on the section of triple tubes,the application of composite trussed continuous beam bridge with concrete-filled rectangular steel tube(CTC-R) was studied in this article,the main completed tasks and conclusions are as the followings:1) It’s focused on the development situations of composite bridges at home and abroad, and paid more attention to the various applications of concrete filled steel tube structure in the domestic bridge.2) Structural measures of composite truss was reorganized,and the emphases was put on the constitution design of floor deck and the chord,the relevant calculation method of the overall bearing capacity、the member bearing capacity and the joint bearing capacity of composite truss were summed up.3) It elaborated the transfer mechanism of the composite truss and put forward the idea of grading-design on rectangular steel tube. The main paraments influencing economic indicators and mechanical properties of CTC-R,such as arrangements of truss braces、angle of inclination of truss braces、the height-span ratio、the composition of truss cross section were analysed by using the finite element analysis.4) Based on practical engineering background,experimentally design and study of CTC-R which has equal spans have been done.5) Comparing with the traditional concrete girder bridge, the CTC-R has more significant advantages in the aspect of technical economy and the mechanical properties. So it certainly has wide prospect of application in the construction of the bridge.