Abstract
A method is presented for equi-linearized seismic response analysis of multi-layered ground including frequency dependent effect of shear modulus and damping on ground motion amplification. The frequency dependent equivalent strain in proportion to the Fourier amplitude of shear strain time history is defined for evaluation of shear modulus and damping factor depending on the frequency contents. The method is examined in the strong motion array records and minutely serveyed soil profile at array observation station located at very soft ground. Superoprity of the presented method to the conventional equi-linearized method is demonstrated especially in case of strong ground motion level and soft ground condition.
