Analysis On The Mechanical Performance Of Continuous Combination Curved Box Girder With Corrugated Steel Webs

With the development of my country’s transportation industry,the requirements for bridge spans are constantly improving.The increase of span will cause a series of problems such as excessive structural weight,serious mid-span deflection,and excessive prestress loss.The birth of composite box girder with corrugated steel webs can just solve the trouble caused by the above problems.At present,a large number of researches have been carried out mainly on simply supported composite box girder with corrugated steel webs at home and abroad,while research on continuous composite curved box girder with multi-span corrugated steel webs is still relatively small.This paper focuses on the mechanical performance of continuous composite curved box girder with corrugated steel webs and combines theory and finite element research.The main research results are as follows:(1)Considering the influence of the bending-torsion coupling effect,shear deformation and shear lag effect,the control differential equation of the simply supported composite curved box girder with corrugated steel webs is obtained by the energy method;This differential equation is combined with the three-bending moment method to solve the internal force of the continuous composite curved box girder with corrugated steel webs,and finally the theory is supported by the finite element model.It is verified that the method proposed in this paper has good applicability for solving the internal force of three-span continuous composite curved box girder with corrugated steel webs.(2)The internal force results obtained by the method in this paper ignoring the shear deformation and the curved bar structure mechanics method are very close.Explanation:The curved bar structure mechanics method ignores the influence of shear deformation when solving the internal force of the curved box girder,and the shear deformation does have an effect on the internal force of the bridge span.(3)The normal stress of the mid-span section of the continuous composite curved box girder with corrugated steel webs is mainly borne by the top and bottom plates,while the shear stress is mainly borne by the webs.And the shear stress of the web gradually decreases with the increase of the height of the web,the thickness of the web and the wave height.When the curve radius changes,the stress of the mid-span section will not change significantly.(4)Under the action of uniformly distributed load,the most unfavorable stress in the section of continuous composite curved box girder with corrugated steel web appears at the contact position between the web and the top and bottom plates;Under the action of concentrated load in the middle of the main span,the most unfavorable stress on the section appears at the point of action of the concentrated load.Therefore,during the construction process,it is necessary to strengthen the protection of the contact position of the corrugated steel web and the concrete top and bottom plate and the cross section of the concentrated load.