Research On Shear Behavior Of Prestress Concrete Composite Box Girder With Corrugated Steel Webs

Prestress concrete composite box girder with corrugated steel webs represents a new innovative system which has emerged in the past decade for bridges. The new system combines the usage of corrugated steel plates as webs and prestress concrete slabs as flanges. This kind of structure is more economical and improves the aesthetic. Currently, few prestress concrete composite box girders with steel corrugated webs were used in china, it is urgent to improve china's level of design and construction of this kind of structure. In this research, the main purpose was to solve a series of critical problems on shear behavior and design method of prestress concrete composite box girder with steel corrugated webs through finite element analyses and test investigation.Test investigation combined with finite element analyses on the shear behavior was conducted. The test data including deflection and strain distribution were obtained. The test specimen was analyzed using finite element model to simulate the process of load, and the stress distribution and deflection were obtained. Comparing the results of finite element analyses and that of test investigation, the shear behavior of prestress concrete composite box girder with corrugated steel webs was mastered.Results from many shear strength tests conducted on girder specimens with corrugated webs are available in the literature wherein both local and global shear buckling modes have been observed. Through a systematic analysis of these data and the shear buckling strength formulas, the coincidental extent of each formula was present. As a result, a semi-empirical formula was developed by regression analyses.Parametric studies were conducted using finite element models and test specimens, the results of test and a finite element analysis was compared. Simulating the presence of initial dimensional imperfections in the webs by uniform imperfections modes method, the result indicate that the structures with corrugated webs were not sensitive on imperfections. Thickness imperfection of webs was introduced into finite element model calculation, the result indicate that the thickness imperfections had influence on the shear buckling strength slightly.The shear resistant design method of structures with corrugated webs was studied. The calculation method of shear stiffness and the checking computations of shear stress were developed. And the recommendations of calculation method of local shear buckling strength, global shear buckling strength and interactive shear buckling strength were made.