Experimental Study on the G(max) Characteristics of the Sand-Silt Mixed Soil Materials Using Bender Element Testing

To study the small strain shear modulus (G(max)) of saturated sand-silt mixed soil materials, a series of tests were conducted using the bender element apparatus, and the influences of fines content (FC), relative density (D(r)), and effective confining pressure ([Formula: see text]) were taken into consideration. The test results indicate that the G(max) of the mixed soil materials decreases first and then increases with the FC up to 100% with D(r) = 35% and 50%, while the G(max) decreases with the increasing FC when D(r) = 60%. Moreover, for a given D(r), the G(max) increases with the increasing [Formula: see text] , and the increase rate keeps constant under various FCs. The G(max) of specimens under various FCs decreases with the increase of the void ratio (e). The decrease rate between the G(max) and e differs when the [Formula: see text] is given, which is influenced by the FC. The G(max) of the mixed soil materials can be evaluated by the Hardin model when the FC is determined. The best-fitting parameter A of the Hardin model first decreases and then increases as FC increases. The revised Hardin model, considering the influence of FC, [Formula: see text] , and e, can be used to evaluate the G(max) for different types of sand-silt mixed soil materials. The error between the evaluated and tested G(max) is less than 10%.