ANALYTICAL PREDICTION OF EARTHQUAKE-INDUCED PERMANENT DEFORMATIONS

A general method is presented for the prediction of earthquake-induced permanent deformations of foundations resting on sand. Predictions are based upon experimental results from common static and cyclic tests; they may take into account various boundary and drainage conditions and require reduced computational effort. The method uses and further develops previous work aimed at the prediction of permanent drift of offshore foundations due to the action of ocean waves. The basic concepts of the method are presented in detail, with emphasis placed upon the introduced improvements and modifications. The versatility of the constitutive laws used to describe permanent strain accumulation in the sand is demonstrated through comparison with data from cyclic laboratory tests. The overall accuracy of the method is evaluated on the basis of actual field observations and experimental measurements.