Soft soil improvement by rigid inclusions under vertical cyclic loading: numerical back analysis
Soft soil improvement by rigid inclusions under vertical cyclic loading: numerical back analysis
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DOI：
10.1080/19648189.2018.1531268
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发表时间：
2021-02-23
影响因子：
2.1
通讯作者：
Emeriault, Fabrice
中科院分区：
文献类型：
--
作者：
Houda, Moustafa;Jenck, Orianne;Emeriault, Fabrice
虽然刚性夹杂体改善体系在单调加载下的行为是众所周知的，但由于缺乏对颗粒平台中载荷传递机制的了解，循环加载下的响应尚未完全理解，也无法预测。本文提出了准静态垂直循环荷载作用下的三维数值模拟方法。将数值计算结果与三维小比例尺模型的实验结果进行了比较，讨论了数值计算过程和实现的本构模型。对于荷载传递平台，建立了剪切硬化弹塑性模型；对于软土，采用改进的Cam Clay模型，因为它具有良好的压缩和膨胀特性。系统行为的某些方面可以正确地再现，例如单调加载下包裹体的载荷和沉降，沉降积累和沿循环加载转移到包裹体上的载荷的减少，以及放置在平台表面的刚性板对沉降积累的定性影响。然而，其他特征不能令人满意地考虑在内，即刚性板在循环荷载下的行为，即夹杂物的荷载。
While the behaviour of rigid inclusion improvement systems under monotonic loading is well known, the response under cyclic loading is not yet fully understood and cannot be predicted due to the lack of knowledge about the load transfer mechanisms in the granular platform. This article proposes a three-dimensional numerical modelling under a quasi-static vertical cyclic loading. Numerical results are compared to experimental results obtained on a three-dimensional small scale model, to discuss the numerical procedure and the constitutive models implemented. For the load transfer platform, a shear hardening elastoplastic model is implemented; for the soft soil, the modified Cam Clay model is used, as it features well the compressive and swelling behaviour. Some aspects of the behaviour of the system could be correctly reproduced, such as the loads on inclusions and the settlements under monotonic loading, the settlement accumulation and the decrease of the load transfer onto the inclusions along the cyclic loading, as well as the qualitative influence of a rigid slab placed at the platform surface on the settlement accumulation. However, other features could not be satisfactorily taken into account, namely the behaviour under a rigid slab submitted to cyclic loading in terms of load on the inclusions.