Simple Method for Dynamic Impedances of Pile Groups
In this paper, a simple method of analysis based on physically approximate modelling is presented for computing the dynamic impedances of pile groups installed in a homogeneous surface stratum lying on rigid bedbrock, where the impedances play an essentially important role in coupling to structures exposed to seismic excitation. This simple method for dynamic impedances of pile groups possesses the remarkable features that the behaviour of the range from stiff and short piles to flexible and long piles is considered in the simple expression, computation of multi-order inverse-matrix or characteristic equation is not involved, and this method is applicable to various arrangement of floating piles. The verification of this method is performed from comparison with the previous analytical results of the dynamic impedances of pile groups oscillating harmonically. The results by the proposed method are sufficiently accurate and readily useful in practical situation without much computational effort.
Departmental Bulletin Paper