A simplified method of calculating the impedance and foundation input motion of foundations with a large number of piles

highlights
• A simplified method is proposed for the impedance and foundation input motion.
• The accuracy of the simplified method is verified by the rigorous method.
• The simplified method is suitable for the horizontal impedance.
• The simplified method is suitable for rocking impedance in low frequency domain.

AbstarctA new simplified method is developed for the analysis of the impedance and foundation input motion of foundations with a large number of piles. In this proposed method, the neighboring piles are replaced by a single equivalent pile. This process of replacement reduces the number of degrees of freedom, computer memory requirement, and calculation time. To validate the simplified method, the impedance and foundation input motion of a raft foundation and an embedded foundation supported by piles groups are calculated through both the simplified method and the rigorous numerical method. Results show that the proposed simplified method for the impedance and foundation input motion of a foundation with a large number of piles has sufficient accuracy and good computational efficiency.