Estimating drained cross-anisotropic elastic parameters in saturated clays using the undrained properties: Fid-Bau Portal

Estimating drained cross-anisotropic elastic parameters in saturated clays using the undrained properties

Pegah, Ehsan / Liu, Huabei / Gholami, Ali

Abstract The accurate determination of anisotropic small-strain stiffness properties in natural soil deposits is of crucial importance in many geotechnical and geological engineering analyses. Accordingly, the main objective of this study is to propose an approach for evaluating the drained elastic stiffness parameters in saturated clays using the undrained properties. To attain this objective, by assuming cross-anisotropy in clayey soils, it is shown that two measured anisotropic components of shear moduli and the vertical component of Young's modulus in the undrained conditions possess the main contributions. They were then combined with a series of theoretical equations and empirical assumptions in the literature representing the relationships between the drained and undrained elastic parameters to yield the estimated values for the anisotropic drained Young's moduli. To verify the reliability of the suggested approach, the anisotropic elastic properties of 51 clayey soil specimens from 21 different soil types relating to 15 various sites in 4 countries were collected based on the experimental laboratory tests reported in literature. The anisotropic drained Young's moduli in each specimen were estimated through the proposed technique and then compared with directly measured ones with satisfactory agreement. The findings of this study may serve as the convenient references for economic and precise determination of in-situ elastic stiffness parameters in cohesive soil deposits using the non-invasive seismic surveying.

Highlights • An approach is proposed to estimate the drained elastic parameters in saturated clays using the undrained ones. • Cross anisotropy is assumed in the elastic properties of saturated clay. • Theoretical equations relating undrained and drained elastic properties are used together with empirical relations. • The proposed approach is validated against a large database of test results.