Analytical study of the main causes of damage to pile foundations during the 2011 off the Pacific coast of Tohoku earthquake

摘要

The authors performed static analyses using a foundation structure model to simulate the process leading to distinctive damage to pile foundations during the 2011 off the Pacific coast of Tohoku earthquake. Notable aspects of the analytical method used for this simulation include consideration of the nonlinear load‐deformation characteristics of pile elements, the dependence of the rotational stiffness at the pile head on the axial load, and the nonlinear behavior of soil spring including the pile group effect. The results of the simulations of pile failure for each loading direction provide a useful explanation of the observed damage to pile foundations. The proposed analysis method can be considered a practical approach to the seismic design of foundations subject to severe earthquakes.