Mechanical behavior of frozen soils: Experimental investigation and numerical modeling
Mechanical behavior of frozen soils: Experimental investigation and numerical modeling
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DOI：
10.1016/j.compgeo.2021.104361
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发表时间：
2021-10
影响因子：
5.3
通讯作者：
Ajay Shastri;M. Sánchez;X. Gai;Moo Y. Lee;T. Dewers
中科院分区：
文献类型：
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作者：
Ajay Shastri;M. Sánchez;X. Gai;Moo Y. Lee;T. Dewers
冻土的力学行为在寒冷地区建筑物和基础设施的设计、施工和维护中起着核心作用。我们介绍并讨论了一项关于阿拉斯加冻土的力学行为的实验活动的主要结果。该数据集是独一无二的，因为它涉及天然冻土，涵盖了广泛的温度范围(即从−6°C到−26°C)和限制条件(即从无约束条件到54.6兆帕的围压)。提出了冻土弹塑性模型，并根据试验结果进行了验证。弹塑性模型考虑了温度和低温吸力对与冻土特性有关的关键性质的影响，即随着温度的降低，前期固结压力、刚度和强度增加。其他方面，如冻土在不同温度下的体积行为，以及弹性和塑性状态之间的平滑过渡，也被该模型定性地捕捉到。在完全耦合的热-水-力模拟器中实现了本构模型，并对融化地基中基础的行为进行了分析。该方法能够很好地反映冻土的主要行为特征。
The mechanical behavior of frozen soils plays a central role in the design, construction, and maintenance of buildings and infrastructure in cold regions. We present and discuss the main results of an experimental campaign focused on the mechanical behavior of frozen soils from Alaska. The data set is unique because it involves natural frozen soils and covers a wide range of temperatures (i.e., from −6 °C up to −26 °C) and confinements (i.e., from unconfined conditions up to a cell pressure of 54.6 MPa). An elastoplastic model for frozen soils is presented and validated based on the test results. The elastoplastic model accounts for the effects of temperature and cryogenic suction on key properties associated with frozen soil behavior, namely, increase of preconsolidation pressure, stiffness, and strength with the decrease of temperature. Other aspects such as the volumetric behavior of frozen soils at different temperatures and the smooth transition between elastic and plastic states are also qualitatively well captured by the model. We implemented the constitutive model in a fully coupled thermo-hydro-mechanical simulator and we analyzed the behavior of a foundation in a thawing ground. The proposed approach is able to capture the main feature of frozen soil behavior.