Homg Hyh Yang - West Virginia University Institute of Technology/Department of Civil Engineering, Montgomery, West Virginia, U.S.A

The soil strength parameters (cohesion and friction angle) applied in the active aspect of retaining structure design or deep excavation analysis are based on the results obtained from the traditional drained or undrained axial compression triaxial shear test. However, the axial compression test does not represent the real soil lateral extension behavior for which such parameters are sought and also the volume change behavior under drained condition. This paper has presented a successful process to predict the lateral extension behavior from a series of traditional axial compression shear tests under multi-confining pressures. A modified version of Hooke’s law is employed herein to predict the drained lateral extension behavior from a series of drained axial compression test results associated with an isotropic rebound volumetric change. The detail of the modified Hooke’s law applied in this research has well presented to support the theoretical transfer process. The logical idea for the prediction of the drained lateral extension strength from the traditional drained axial compression test can be illustrated through the development of stress paths that the stress path of a drained lateral extension test can be intersected by many other stress paths of the drained axial compression tests in multi-combination of effective confining pressures. The drained lateral extension test behavior of deviatoric stress and volumetric strain versus axial strain curves which are achieved from multi-tests applying in Nevada sand. The fundamental behavior of interest in both the drained lateral extension and the drained axial compression tests is the stress-strain-strength behavior and the volume change. The test results from the drained lateral extension tests are successfully evaluated from a series of drained axial compression tests response coupled with the sand’s associated drained isotropic rebound behavior.

lateral extension test, axial compression test, triaxial shear test, stress path, Hook’s law