Abstract Coarse-grained soils are important geotechnical materials widely used in construction. The contribution of particle size distribution on the small strain shear modulus Gmax of coarse-grained soils has not yet been fully recognized. This paper presents an experimental investigation into the effects of the uniformity coefficient Cu and the mean particle size D50 on the small strain shear modulus of coarse-grained soils. To this end, a series of shear wave velocity tests were conducted at different confining stresses and void ratios on reconstituted specimens covering a wide range of particle size distributions. All tests were performed by taking advantage of a custom-developed measurement device in a large-scale triaxial apparatus. The results demonstrate that Cu and D50 have pronounced but opposite effects on Gmax. Specifically, Gmax decreases with Cu and increases with D50. The effects of Cu and D50 were then quantified to generate two types of empirical equations, type-A and type-B, that are representative of a broad family of Gmax equations accounting for the influence of particle size distribution. The equations are tuned based on model parameters A, x and n. In both equations, n is a function of Cu. The difference between the two types of equations is that x is the function of Cu and D50 and A is the function of Cu in the type-A equation, while x is constant and A is the function of Cu and D50 in the type-B equation. The proposed equations for predicting Gmax were used to produce acceptable estimates for both coarse-grained soils in this study and from existing literature. The findings acquired from this study are expected to provide a reference for estimating the small strain shear modulus of coarse-grained soils at the beginning of the project when the test data have not yet been obtained.

中文翻译：

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粗粒土小应变剪切模量预测

摘要 粗粒土是建筑工程中广泛使用的重要岩土材料。粒度分布对粗粒土小应变剪切模量 Gmax 的贡献尚未得到充分认识。本文对均匀系数 Cu 和平均粒径 D50 对粗粒土小应变剪切模量的影响进行了实验研究。为此，在不同的围压和空隙率下，对覆盖广泛粒径分布的重构试样进行了一系列剪切波速度测试。所有测试都是通过在大型三轴设备中利用定制开发的测量设备进行的。结果表明，Cu 和 D50 对 Gmax 具有明显但相反的影响。具体来说，Gmax 随 Cu 减少，随 D50 增加。然后量化 Cu 和 D50 的影响以生成两种类型的经验方程，A 型和 B 型，它们代表了考虑粒度分布影响的广泛的 Gmax 方程族。方程根据模型参数 A、x 和 n 进行调整。在这两个方程中，n 是 Cu 的函数。两种方程的区别在于，A型方程中x是Cu和D50的函数，A是Cu的函数，而B型方程中x是常数，A是Cu和D50的函数方程。用于预测 Gmax 的建议方程用于在本研究和现有文献中对粗粒土壤产生可接受的估计。