Reliability Research For Composite Girder Bridge With Corrugated Steel Webs

With the increasing number of composite girder bridges with corrugated web steel girders(CWSGs)under construction or completed in our country,the purpose of this thesis is to improve the safety and reliability of composite girder bridges with corrugated steel webs by doing research for the reliability of bearing capacity of composite girder bridges with CWSGs and recalibrating the resistance factor according to the Chinese Highway Bridge Code.It is of great significance to the design and construction of composite girder bridges with CWSGs in China.In this thesis,the statistical parameters of vehicle load under two kinds of traffic status on the composite girder bridge with CWSGs are adjusted by comparing the differences of vehicle load between old and new Chinese Highway Bridges Codes.By collecting and organizing the statistics from papers,the uncertainty coefficient of material,fabrication and professional factors are obtained.Based on the Chinese Code,this thesis calculates the reliability indexes of shear bearing capacity,bending bearing capacity and the series system of steel-concrete composite girder bridge which recommended by AASHTO through the check point method and the importance sampling Monte Carlo method.A series of sensitivity analyses were carried out to quantify the relative contribution of each design parameter to the overall reliability of CWSGs in shear and bending.The findings of this study suggest that,for CWSGs in shear and in bending,the resistance factors should adjust to be 1.119 and 1.057 are appropriate to ensure a reliability level that is consistently close to the target.The sensitivity analysis showed that the web thickness,web depth,flange thickness,and the yield strength of the web’s steel material are the most influential parameters on the reliability index of CWSGs.