Study On Mechanical Properties Of Partially Cable-stayed Bridge With Corrugated Steel Webs

Cable-stayed bridges with corrugated steel webs combine organically with two new bridges,“corrugated steel web bridges” and “dwarf tower cable-stayed bridges”.The use of corrugated steel web composite box girder bridges can effectively avoid the common cracking of webs in prestressed concrete box girder bridges.Besides,the structure can give full play to the advantages of high prestressing efficiency,reduced weight,short construction period.The bridge can realize the new bridge type of rigid and soft.Due to the above advantages,some cable-stayed bridges with corrugated steel webs have been widely used in bridge projects at home and abroad.In order to further promote the engineering application of cable-stayed bridges with corrugated steel webs and provide theoretical models and scientific basis for the new bridges,this paper combines the theoretical analysis and numerical simulation methods for the live-load ratio of cable beams and the cable-free zone.The length and stiffness of the structure were studied.The main research work and conclusions included:(1)On the basis of considering the influence of axial force,the formula applied to the beam liveload ratio with corrugated steel web is derived by using the typical beam theory.In order to verify the accuracy of the formula,the cable/beam live-load ratio of cable-stayed bridge with corrugated steel webs is analyzed by the formula,and the results are compared with the results of the finite element model verified by the model.(2)The method of experimental research and numerical simulation was used to verify the accuracy of the beam live-load ratio formula.The results show that the cable beam live-load ratio formula has higher accuracy.Using the finite element model and the formula in the paper to research the parameter analysis,the influence of the cable inclination,the cable area and the moment of inertia of the main beam on the cable/beam live-load ratio of the cable girder of the corrugated steel webs,and the applicability of the formula is clearly defined.(3)Based on the numerical simulation method,the parameters such as the side span ratio,the length of the non-cable zone beside the tower,the length of the cable free zone in the middle span,and the form of the web form influence the internal force and deformation of the partially cablestayed bridge of corrugated steel web.The analysis shows that under the condition of different cable free zones,the internal force and deformation of the main girder change more obviously,and the longitudinal displacement of the bridge tower is less deformed.Comparing the internal forces and deformations of some cable-stayed bridges with different webs under different cable-free conditions,the results of the deformation and internal force of the main girder of some cable-stayed bridges with concrete webs and cable-stayed bridges with corrugated steel webs are in good agreement.Besides,cable-stayed bridges with flat steel webs and some cable-stayed bridges with corrugated steel webs,there are certain deviations in the internal forces and deformations of the main girder under different cableless zone lengths.(4)Based on the theoretical analysis,the conclusion is that there is not much difference between the stiffness ratio of the tower girder of the cable-stayed bridge with corrugated steel web and the typical cable-stayed bridge.The numerical simulation method was used to analyze the parameters,and the effects of the height of the tower,the height of the main girder,the grade of the concrete material of the girder and the form of the web on the internal forces and deformation of the cablestayed bridge with corrugated steel webs were quantitatively studied.