| Continuous girder and suspension bridge is a new type of bridge structure combining continuous girder bridge and self-anchored suspension.This type of bridge is beautiful,easy to construct and economical.It combines the advantages of continuous girder bridge and suspension bridge,and makes up for the disadvantages of each other through the combination of both.However,as a new bridge structure,there are not many engineering examples at home and abroad,so it is necessary to study it in depth.This paper constructs a continuous girder and suspension bridge based on the parameters of a self-anchored suspension bridge.The finite element models were developed using MIDAS/CIVIL and CSI BRIDGE finite element software to study the hydrostatic properties.The main work of this paper is as follows.(1)The static characteristics of the continuous girder and suspension bridge were analyzed by establishing a finite element model and compared with those of a self-anchored suspension bridge of the same span,and the differences in the static characteristics of the main girder deflection and main girder bending moment between the two structures under load were investigated.The results show that after adding the continuous girder section,the span deflection of the continuous-suspension collaborative system is reduced by 31.29%,the main cable tension is reduced by 19.07%,and the distribution of main girder bending moment is more reasonable under the same load.(2)The static parameters analysis of the continuous-suspension collaboration system was carried out,and it was found that with the decrease of the vertical-to-span ratio,the increase of the internal force of the main cable reached 30.25%,and the axial force of the main beam also increased by 25.4%,while the boom force gradually decreased.With the increase of the edge-to-span ratio,the main beam axial force increases by 27.8%,while the changes of the main beam bending moment and boom stress are not significant,and the vertical deflection of the main beam increases first and then decreases.With the increase of the tensile stiffness of the main cable,the reduction of the main beam bending moment is great,reaching 28.5%.With the increase of main beam flexural stiffness,the decrease of main beam deflection is 40.8%,while the increase of main beam bending moment is 32.4%.With the increase of the boom tensile stiffness,the increase of the main cable internal force and boom force is larger,increasing 28.1% and 13.2% respectively,while the vertical deflection of the main beam is effectively reduced.(3)The self-vibration characteristics of the continuous girder and suspension bridge were studied,and it was found that the self-vibration frequency of the collaborative system was greater compared with that of the self-anchored suspension bridge,and there was no longitudinal drift,which is common in suspension bridges,indicating that the vertical stiffness of the structure is greater,but transverse vibration occurred many times,indicating that the transverse stiffness is smaller.(4)The response spectrum analysis of the continuous girder and suspension bridge under E1 and E2 earthquakes and the time course analysis under E2 earthquake were studied.From several main control sections,the largest longitudinal displacement appears on the top of the bridge tower,the relatively large transverse and vertical displacement appear on the spanwise section of the main girder.However the vertical displacement of the structure as a whole are small and negligible.The results of the two methods were compared and analyzed to determine the seismic performance and the relative magnitude of the three-way stiffness of the bridge.Figure[40] Table[53] Reference[57]... |
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