Study On Static Performance Of Long Span Concrete Filled Steel Tubular Arch Bridge

The construction of concrete-filled steel tubular arch bridge has been extensively promoted in China,and the concrete calculation theory is becoming more and more perfect.At present,the national standard,industry norms and local standards have been promulgated about concrete-filled steel tubular arch bridge and in 2015 the Ministry of Transport has issued a concrete-filled steel arch bridge design specifications,namely?Design Code for Concrete Filled Steel Tubular Arch Bridge?JTG/T D65-06-2015,so that the design of concrete-filled steel tubular arch bridge has become well documented.The focus of this paper is the problem of the arch axle coefficient and the height of the arch rib in the cross-section design of the CFST arch bridge.The arch axis coefficient and the height of the arch rib section are important design parameters of the large span CFST arch bridge,which not only affects the control of the engineering quantity and the total cost of the whole construction process,but also affects the static performance of the whole bridge.In order to study the influence of the arch axis coefficient and the height of the arch rib section on the mechanical performance of the main arch rib of the large span CFST arch bridge,which provides a reference for the designer to choose the arch axis coefficient reasonably and determine the reasonable arch rib section height.According to the?Design Code for Concrete Filled Steel Tubular Arch Bridge?,the finite element analysis model of the Midas model of is established which taking Daxiao Jin bridge as the engineering background,the variation law of the mechanical properties are studied of the arch ribs and the concrete in the arch ribs with different arch axis and different arch rib height.The main research contents are as follows:(1)The influence of the change of the arch shaft coefficient on the mechanical performance is analyzed.In order to determine the design of upper and lower arch axis according to?Highway Bridge Design Handbook:Arch bridge?appendix table,the finite element model of the bridge is established based on Daxiao Jin bridge.In the three different arch axis,The influence of the arch coefficient on the mechanical properties of the arch ribs is compared and analyzed.(2)The influence of the height of arch ribs on the mechanical performance of main arch ribs is analyzed.Without changing the original design arch shaft coefficient,vector span ratio and variable height arch rib section under the premise of the law,1)The calculation model is established without changing the height of the original skewback section but the height of the vault section.(2)The calculation model is established without changing changing the height of the original vault section but he height of the skewback section.The influence of changing the height of the arch rib on mechanical performance of the arch rib of the large span CFST arch bridge and the concrete in the pipe is analyzed.(3)The results of the influence of the change of the arch axis coefficient and the height change of the arch rib cross section are analyzed.The design optimization is put forward for the original design,which is the key parameter of the arch axle coefficient and the arch rib height in the design process of the CFST arch bridge to provide a reference.