The Earthquake Engineering Online Archive

Seismic modelling of deep foundations

Chen, Cheng-Hsing; Penzien, Joseph

UCB/EERC-84/19, Earthquake Engineering Research Center, University of California, Berkeley, 1984-11, 136 pages (535/C45/1984S)

The hybrid modeling approach, which can effectively solve three-dimensional soil-structure interaction problems, is generalized for applicability to deep foundations. This is achieved by partitioning the entire soil-structure system into a near-field and a far-field using a cylindrical interface positioned very close to the structure-soil interface. The near-field is modeled by finite elements while the far-field is modeled by an impedance matrix obtained through application of the global Ritz method. The resulting impedance matrix is fully coupled, complex-valued, and frequency dependent and can be combined with any compatible near-field for the purpose of carrying out complex response analyses of foundations. Impedance matrices corresponding to different geometries of cylindrical interfaces have been generated and used for dynamic analyses of some typical foundations such as plates, cylinders, caissons, and piles. Results obtained with this method are compared with other published solutions.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-84-19.pdf (26 MB)