Influence of non-plastic fines content on maximum shear modulus of granular materials

摘要

Resonant column tests were conducted on clean Hostun sand and Hostun sand mixed with 5%, 10%, 20%, 30% and 40% fines (particle size smaller than 0.075 mm) to assess the influences of void ratio (e), effective confining stress (p') and fines content (f(c)) on the maximum shear modulus, G(max). A significant reduction of G(max) was observed with increasing f(c). While the Hardin's empirical relation was adequate to capture the influence of e and p' on G(max), each sand with an f(c) has to be considered as separate soil. The micro-CT scans of these sand with fines mixture provided a qualitative observation of the initial skeleton structures of the "fines-in-sand" or "sand-in-fines" of equivalent granular void ratio, e*. Therefore, e was replaced by e* in Hardin's relation for clean Huston sand to overcome the effect of f(c). The conversion of e to e* requires two parameters: b and in. Four different approaches, including the calibration of b and m, were used to obtain e* and to verify the performance of e* in capturing the effect of f(c). The performances of the calibrations, in terms of the root-mean-square-deviation and R-2, are discussed. The G(max) of Hostun sand with a range of f(c) can be predicted with good accuracy using Hardin's relation for clean Hostun sand when e is replaced by e*. Then, collected data sets from the literature were also analyzed to validate e* in capturing the effect of f(c). (C) 2016 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V.