This paper induces the reduction factor of the total input energy for long-period ground motions due to the damping in the elastic single-mass system. The paper investigates the evaluation formula by response analysis using same method applied in the previous research. The analysis uses long period ground motions on the free surface of engineering bed rock for four districts of Kanto, Shizuoka, Chukyo, and Osaka announced by the MLIT, considering ground amplification of soil. Finally, this paper proposes formula as a function of damping factor and building period. The formula shows excellent suitability with analytical results.
