An experimental database for the development, calibration and verification of constitutive models for sand with focus to cyclic loading: part II—tests with strain cycles and combined loading
An experimental database for the development, calibration and verification of constitutive models for sand with focus to cyclic loading: part II—tests with strain cycles and combined loading
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DOI：
10.1007/s11440-015-0412-x
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发表时间：
2016-08
期刊：
影响因子：
5.7
通讯作者：
T. Wichtmann;T. Triantafyllidis
中科院分区：
文献类型：
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作者：
T. Wichtmann;T. Triantafyllidis
对于地震荷载作用下岩土结构的数值研究，为了检验液化可能导致的破坏，使用复杂的土体本构模型是必不可少的。这种模型必须充分描述材料在恒定体积(不排水)条件下对循环载荷的响应，其中包括有效应力的松弛(孔压累积)或在足够大的循环次数(循环迁移率、应力吸引子)后重复通过的有效应力环。土体在不排水循环荷载作用下的特性是多种多样的，这取决于初始条件(例如密度、组构、有效平均压力、应力比)和荷载特性(例如循环的幅度、应力或应变循环的施加)。为了开发、校准和验证以不排水循环加载为重点的本构模型，需要从包含各种初始条件和加载特性的高质量实验室测试中获得数据。这两篇配套论文的目的是为细砂采集提供这样的数据库。第二部分集中于应变循环的不排水三轴试验，其中已研究了大范围的应变幅度。此外，还讨论了固结压缩和各向同性压缩试验，以及不加荷和加荷循环的排水三轴试验。在不排水的三轴试验中，还研究了单调和循环联合加载。这里提供的所有测试数据都可以从第一作者的主页上获得。作为现有本构模型检验的一个例子，将实验数据与采用沿晶应变的亚塑性单元试验模拟进行了比较。
For numerical studies of geotechnical structures under earthquake loading, aiming to examine a possible failure due to liquefaction, using a sophisticated constitutive model for the soil is indispensable. Such model must adequately describe the material response to a cyclic loading under constant volume (undrained) conditions, amongst others the relaxation of effective stress (pore pressure accumulation) or the effective stress loops repeatedly passed through after a sufficiently large number of cycles (cyclic mobility, stress attractors). The soil behaviour under undrained cyclic loading is manifold, depending on the initial conditions (e.g. density, fabric, effective mean pressure, stress ratio) and the load characteristics (e.g. amplitude of the cycles, application of stress or strain cycles). In order to develop, calibrate and verify a constitutive model with focus to undrained cyclic loading, the data from high-quality laboratory tests comprising a variety of initial conditions and load characteristics are necessary. It is the purpose of these two companion papers to provide such database collected for a fine sand. Part II concentrates on the undrained triaxial tests with strain cycles, where a large range of strain amplitudes has been studied. Furthermore, oedometric and isotropic compression tests as well as drained triaxial tests with un- and reloading cycles are discussed. A combined monotonic and cyclic loading has been also studied in undrained triaxial tests. All test data presented herein will be available from the homepage of the first author. As an example of the examination of an existing constitutive model, the experimental data are compared to element test simulations using hypoplasticity with intergranular strain.