Study On The Shear Buckling Problems Of Corrugated Steel Webs-RPC Composite Girder Bridge

Compared with traditional prestressed concrete composite beams,corrugated steel web with reactive powder concrete(RPC)composite girder can reduce the self-weight of the box girder greatly by replacing the top and floor concrete plate with ultra-high performance RPC concrete and replacing the concrete webs with corrugated steel webs,improve the load effect of the structure,increase the span of the composite beam.Therefore,it can be applied to the long-span bridge structure.For the continuous rigid frame bridge with long span corrugated steel webs-RPC composite box girder,the shear buckling of corrugated steel web is the main factor limiting its application.This paper makes a special analysis on this problem,the following major works were carried out in this dissertation:(1)For the continuous rigid frame bridges with the span arrangement of 141m+250m+141m,the traditional continuous rigid frame bridge scheme of prestressed concrete and the continuous rigid frame bridge scheme of corrugated steel webs-RPC composite box girder were designed.Through the computational and analysis finds that the maximum midspan deflection of continuous rigid frame bridge with corrugated steel webs-RPC composite box girder is 2 times the maximum deflection of the traditional prestressed concrete continuous rigid frame bridge.This is mainly caused by the excessively low height of the continuous rigid frame bridge with corrugated steel webs and RPC composite box girde.However,as the beam height increases,the corrugated steel webs are prone to buckling failure.So it is necessary to further study the shear buckling problem of corrugated steel webs in long-span bridges.(2)For the single-leg corrugated steel webs-RPC composite box girder continuous rigid frame bridge,when the beam height at the root section is? 13 m,its shear buckling strength is insufficient,double-leg corrugated steel webs are required.In this paper,three diffrent beam height of continuous rigid frame bridges with double-leg corrugated steel webs-RPC composite box girders are designed,the variation of shear buckling strength with beam height is studied.The feasibility of the continuous rigid frame bridge with double-leg corrugated steel webs-RPC composite box girder in the long-span bridge is verified.(3)Because of the disadvantages of continuous rigid frame bridge superstructure with double-leg corrugated steel webs-RPC composite box girder,such as heavy weight,complex construction and high cost,a composite corrugated steel web with polyurethane and steel plate is proposed,then the feasibility of the structure is verified.Six kinds of continuous rigid frame bridges with different thicknesses polyurethane composite corrugated steel webs-RPC composite box girders were designed,the applicability of polyurethane combination modes with different thickness is studied.It provides reference for similar bridge design in the future.