Dynamic behavior of vertical shaft under earthquake loadings

Dynamic responses of a vertical shaft subjected to seismic loads in multi-layered soils were evaluated by a three-dimensional Finite Element (FE) approach. The emphasis was on quantifying the soil stratigraphy of site and the deformation of vertical shaft under earthquake loadings. A series of dynamic parametric analyses were performed, including input motions and surrounding soil conditions. Results of the dynamic analysis were compared with the Response Displacement Method (RDM) in terms of the maximum shear force and bending moment on vertical shaft. From the results of FE analysis, it was found that the dynamic response of the vertical shaft was significantly influenced by soil stratigraphy and input motions. It was also found that dynamic analysis results were in a good agreement with RDM calculated by double cosine method, and then the maximum values of shear force and bending moment were occurred near the interface between the soil layers.