Study of the Capabilities of Six Advanced Soil Models to Predict Responses to Complex Strain Paths Typical of Explosively-Induced Ground Motion.

Abstract : The capabilities of six advanced soil models to predict the response of remolded Ralston Valley soil to complex strain paths were investigated in a joint, cooperative effort among several organizations. The complex strain paths were typical of those experienced by soil elements during nearby near-surface explosive ground motion events. The investigation involved both analysis and extensive laboratory testing. Standard laboratory tests were conducted to provide the usual type of data for fitting the models, while non-standard laboratory tests were done to drive the soil around prescribed, fully three-dimensional complex strain paths and simultaneously measure the corresponding stress histories. To avoid possible unknown differences in testing equipment, all laboratory tests were done with a true triaxial device. The models were fit to the data from the standard laboratory tests, and then driven around the prescribed complex strain paths to predict the corresponding stress histories. Comparison between the predicted and measured stress histories formed the basis for evaluating the models. However, because of uncertainties that occurred in the data for the complex strain paths, a meaningful evaluation of the models could not be conducted. Recommendations are given for improving the testing procedures so that data of the required quality can be obtained in the future.