Stiffness of clays and silts: Normalizing shear modulus and shear strain
Stiffness of clays and silts: Normalizing shear modulus and shear strain
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DOI：
10.1061/(asce)gt.1943-5606.0000887
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发表时间：
2013-09
影响因子：
3.9
通讯作者：
P. J. Vardanega;M. Bolton
中科院分区：
文献类型：
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作者：
P. J. Vardanega;M. Bolton
本文分析了细粒土不排水剪切应力-应变数据的数据库，其中包括21个粘土和粉土的67个试验。用初始平均有效应力p‘(即G/p’与对数γ)或不排水抗剪强度cu(即G/cu与对数γ)来归一化割线G在减小不同粘土之间的散布方面远不如使用最大剪切模数Gmax的方法成功，而Gmax仍未被岩土研究人员和本构模型人员普遍采用。对GMAX的半经验表达式进行了分析，提出了一个仅使用空隙比函数和约束应力函数的简单表达式。这比Hardin式的方程要好，并且证明了孔隙比函数是超固结比(OCR)函数的替代。为了推导出在任何所需的工作应变大小下提供割线刚度的可靠估计的关联式，割线剪切模数G是正态的。
AbstractAn analysis is presented of a database of 67 tests on 21 clays and silts of undrained shear stress-strain data of fine-grained soils. Normalizations of secant G in terms of initial mean effective stress p′ (i.e., G/p′ versus log γ) or undrained shear strength cu (i.e., G/cu versus log γ) are shown to be much less successful in reducing the scatter between different clays than the approach that uses the maximum shear modulus, Gmax, a technique still not universally adopted by geotechnical researchers and constitutive modelers. Analysis of semiempirical expressions for Gmax is presented and a simple expression that uses only a void-ratio function and a confining-stress function is proposed. This is shown to be superior to a Hardin-style equation, and the void ratio function is demonstrated as an alternative to an overconsolidation ratio (OCR) function. To derive correlations that offer reliable estimates of secant stiffness at any required magnitude of working strain, secant shear modulus G is norma...