PREDICTION OF SEISMIC POREWATER PRESSURES.

A method is described for representing porewater pressure data from constant stress or constant strain cyclic loading tests on saturated sands as a monotonically increasing function of a single variable called a damage parameter. This parameter allows the data from constant stress or constant strain cyclic loading tests to be applied directly to predict the porewater pressures generated in the field by the irregular stress or strain histories caused by earthquake loading. The new procedure for data description greatly simplifies both total and effective stress dynamic response analyses of saturated sand deposits. It is also an extremely efficient way of storing a large volume of test data. Refs.