Abstract
In order to investigate various nonlinear response characteristics, including buckling, of thin cylindrical shells under vertical and horizontal seismic motion, pseudodynamic experiments and nonlinear response simulation analysis are performed. It is confirmed that buckling is caused mainly by horizontal seismic loads, and that vertical seismic loads reduce the lateral load-carrying capacity of cylinders and amplify the response displacement for a given horizontal seismic load. To evaluate the amplification of nonlinear horizontal responses due to vertical input motions, we define a response amplification factor, which is calculated from the floor response spectra of seismic waves.