Virtual double-layerbeam element model of main beam of composite beam cable-stayed bridge

Abstract:

In order to accurately simulate the interaction between concrete deck slabs and steel girders of steel-concrete cable-stayed bridges and the redistribution of internal forces between the two due to the shrinkage and creep of concrete, according to the internal force distribution characteristics of the composite cross-section and the concrete shrinkage and creep recursive algorithm, a new type of continuous composite girder virtual double-layer beam element was developed. Then the new element was validated and analyzed by using three-span continuous girders and the Chibi Yangtze River Highway Bridge project, with a comparative study conducted against the actual double-layer element commonly used in engineering. The results show that the calculation results of the virtual double-layer beam model are in good agreement with the measured data, and the number of elements can be reduced by about 67% and the calculation speed can be improved by about 40% compared with the actual double-layer model. The new element exhibits high computational accuracy while significantly reducing main girder elements count. It realizes the continuous composition between the interface of steel girder and bridge deck, accurately simulates the shrinkage and creep effects of concrete bridge deck, and also simulates the construction process of steel girder and bridge deck in stages, which provides an improved steel-concrete composite beam simulation method of high accuracy for the composite structure.