Elastic Stiffness of Flared Bridge Columns with Foundation Springs

The elastic stiffness of columns is a parameter extensively used for the dynamic and static analysis of bridges. The analytic exact estimation of this parameter is very complicated when the geometry and boundary conditions of the column are complex. In this case, the use of an approximate method and a computer might be necessary for the solution of the problem. In this paper, an analytic method for the exact estimation of the elastic stiffness of columns with a parabolic flare at the top and translational and rotational foundation springs at the bottom is presented. This complicated geometry type of bridge column has been used extensively by bridge engineers in the design of highway bridges. First, the whole method is presented in detail; then all necessary steps for the application of the method are identified and summarized. Finally, the application of the method to the estimation of the elastic stiffness of the columns of a bridge located at Riverside, California, is shown through an illustrative example.