Analysis For The Effects Of Structural Parameters Of Long Span Steel Truss Arch Bridge

Steel truss arch bridge is widely used because of its beautiful appearance,rigid and flexible structure.With the development of economy technology,the research of steel truss arch bridge is more and more,and the structure parameters in the design process need to be considered.The rationality of the design parameters ensures the normal use of the bridge.This paper first introduces the development and the structural form of long-span steel truss arch bridge.Then the basic theory of calculation is presented,which mainly includes the basic calculation theory of arch bridge stability and nonlinear method etc.Based on an engineering project,the static behavior,elastic stability and ultimate bearing capacity of the structure is calculated.The result shows that the mechanical properties of the bridge are good,and the ultimate bearing capacity of the structure is mainly related to the nonlinearity of the material and rarely related to the geometric nonlinearity.Then,by adjusting the parameters of vector span ratio,system parameter and boom characteristic,the influence of parameters variation on the static behavior,elastic stability and ultimate bearing capacity is studied.It is found that the increase of the vector span ratio in the measured interval has a significant tendency to decrease the internal force and stress of the arch ribs.The influence of the vector span ratio in the section on the stiffness is negligible,and the variation of the vector span ratio has a great impact on the internal force and stress of the beam and D1 boom.The variation trend of structural elastic stability coefficient under different load cases varies with the increase of the vector span ratio,and the ultimate bearing capacity is increasing with the increase of the vector span ratio.The system parameter has a great influence on the internal force and stress of the arch ribs,the rigid connection between the beam and arch is the most unfavorable form,and the hinge connection between the beam and arch is a relatively good form of the structural system.The system parameter has little effect on the stability and the ultimate bearing capacity.The boom fracture has a great influence on the static behavior and the elastic stability coefficient,but the effect of the boom characteristic on the ultimate bearing capacity is not obvious.The asymmetric arrangement of moving loads is unfavorable to the stability of the structure,and the asymmetric arrangement of the moving loads should be considered in the design process.The initial defect has little effect on the ultimate bearing capacity,but the precision must be kept in the construction.