A FINITE ELEMENT METHOD FOR VERTICAL MECHANICS ANALYSIS OF STEEL-CONCRETE COMPOSITE STRUCTURE IN PYLON CABLE ANCHOR ZONE OF LONG SPAN CABLE-STAYED BRIDGE

In steel-concrete composite structure of pylon cable anchor zone in cable-stayed bridge, most of vertical component of applied cable force transfers from steel anchor box to concrete walls through shear studs, but the mechanism of vertical force transfer is complicated and remains unaddressed. After introducing the analytical continuum method, this paper simplifies the analysis problems and obtains the fundamental differential equation which can reveal the vertical mechanics of the composite structure, and then deduces the element stiffness matrix and load vectors for the finite element solution of analysis. This paper also considers the effect of shrinkage and creep on the composite structure at different construction stages in order to obtain best analysis results to describe the real structural behavior. Through an engineering design example, the method proposed in this paper is verified by a comparison of its calculation results with those obtained from complicated 3D finite element method. The proposed method is simpler and more efficient than 3D finite element method, and can be used in structural analysis.