Research On Mechanical Behaviors Of Through Three-hinged Steel Arch Bridge With Rigid Suspenders

With the rapid development of China’s bridge constructio n level, three-hinged steel archbridges are widely used owe to its advantages, such as simple manufacture, convenientconstruction. A systematic study has been conducted on the static performance, space stabilityand fatigue problem of the suspenders. The main works involved in this research are asfollows:Firstly, taking Ling Bridge in Ningbo as the research object, the effect of rise-to-spanratio, arch rib stiffness, arch rib inclination angle, suspenders stiffness and the boundaryconditions are studied systematically in finite element solution. Under the consideration ofintegrated factors of force, construction and the cost, the proper structure is proposed, namelythe rise-to-span ratio from1/5to1/7, parallel arches, vertical suspenders, smaller arch ribrigidity, larger suspenders stiffness. Then the static performance of the Ling Bridge iscalculated in finite element solution, the results meet the specification requirements, whichfurther verify the rationality of such bridges.Then, the study of the structure stability is conducted. Taking Ling Bridge in Ningbo asthe research object, the effect of rise-to-span ratio, the arch rib stiffness, the arch ribinclination angle, the suspender stiffness, and the transverse braces of arch ribs are studied infinite element solution. Some suggestions are given to improve the stability of the structure.The rise-to-span ratio should be a little bigger, increasing the stiffness can improve thestability of the structure to a certain extent, but the arch rib rigidity should not be too big. it isviable to improve the lateral stability of the arch ribs by increasing the stiffness of suspendersand transverse braces or installing more transverse braces.Finally, the fatigue problem of rigid suspender has been discussed. The traditionalfatigue life assessment method of the old riveted steel bridges is studied. Based on thetraditional fatigue life assessment method, the residual fatigue life of Ling Bridge’s rivetedsteel suspenders are calculated in finite element solution, and an anti-fatigue designrecommendation is proposed.