Effect of A Void Ratio On the Small Strain Shear Modulus Gmax for Coarse - Grained Soils

Abstract

This article discus about the small strain shear modulus Gmax and the shear wave velocity vs of coarse-grained soils, depending on their state parameters such as the void ratio e. Bender elements installed in a triaxial apparatus were used as a technique for measuring the small strain properties of the soil tested. Gmax and vs are the basic parameters for evaluations of soil responses due to seismic/dynamic loading and for descriptions of the non-linear behaviour of soil in a wide range of strains. The current designs of shallow foundations (settlement, bearing capacity) are discussed. The review of this topic includes previously published empirical equations for Gmax and a description of measurement techniques for bender elements and their evaluation. Sand from the Danube from the locality of Győr was chosen for the testing. A general description of the material is given. A time domain technique was used for the evaluation of the tests. Various input signals and frequencies were used. The samples were tested in a vacuum confinement. The results are compared with the empirical equations proposed in the reviewed literature. Some issues about the testing method and sample preparation observed during the testing are discussed. The type and frequency of input signals, methods for the interpretation of test results, and measurement discrepancies are analysed. Finally, the authors arrive at conclusions from the current laboratory testing. The effect of the void ratio on Gmax and consequently on vs was confirmed.