Shear modulus and damping ratio characteristics of gravelly deposits

Abstract

In this paper, the results of an experimental investigation of dynamic characteristics of gravelly cobble deposits, such as shear modulus (G) and damping ratio (D), are presented. The gravelly cobble deposits are very common in the Taichung metropolitan area of Taiwan where there is an urgent need to determine G and D for dynamic analysis and design of structures. The test program includes measurements of shear wave velocity by the downhole method and large-scale dynamic triaxial tests and resonant-column tests. Special consideration is given to preparing samples of gravelly cobble deposits for laboratory tests. The "equal-weight replacement method" to scale down the real gravelly deposits to cell diameters is used for the preparation of samples. This method is found to be satisfactory, as consistent and reasonable results are obtained. The results of the present study show that the shear modulus - shear strain (G-gamma) relationship for this gravelly deposit does not follow exactly those reported in the literature. The deviation of this G-gamma relationship from those reported in the literature is investigated and explained

Characterization of Moisture-Dependent Changes in Stiffness of Unbound Aggregate Base Materials in Florida

“…Normalized data points for both materials lie well within the maximum and minimum ranges for gravel soils reported by Seed et al (9). Lin et al and Yasuda and Matsumoto reported similar behavior for gravelly soils (13,14).…”

Linear dynamic properties of sandy and gravelly soils from large-scale resonant tests

“…Seed et al (1986) proposed a set of nonlinear shear modulus reduction and material damping increase curves. Lin et al (2000) used a large-scale cyclic triaxial device with a specimen size of 15 cm (6 in.) in diameter and 30 cm (12 in.)…”

Geotechnical Earthquake Engineering

“…2.2, for example. Lin et al (2000) performed a test program with measurements of transversal wave velocity by the down-hole method and large-scale dynamic triaxial tests and resonant-column tests of gravely deposit from Taichung area of Taiwan. They found that the shear modulus ratio G/G max of the gravely cobble deposits does not decrease below a value of about 0.5 for shear strain greater than 10 −4 , in contrast to sandy soil.…”