This paper combines the equivalent nodal force method suggested by serf et al, (1976) and equivalent inertial force method proposed by Taniguchi et al (1983, 1987). The former is fine to utilize seed\u27s strain potential but the stress-strain curve is obtained only by static test, while the latter uses dynamic stress-strain curve, but the determination of direction of equivalent inertial force is rather difficult. The writers use the equivalent nodal force by average shear stress (τav=0.65 τmax) and assume it\u27s direction to be coincided with static shear stress. Also dynamic stress-residual shear strain curve is obtained by dynamic testing
