Abstract

New thermomechanical models for saturated soils recently developed in the literature very well capture the thermal cyclic deformations of normally consolidated (NC) soils, but this is not the case for slightly overconsolidated (OC) soils. To improve this, a framework based on the reference line (RL) and thermal stabilisation line (TSL) is proposed in the e-ln(p) plane. Whatever the applied thermal solicitations, monotonic or cyclic, the thermoplastic volumetric strains of slightly OC soils are easily predicted from their NC states using the RL and TSL lines concept. It should be noted that the TSL already exists in the literature but requires at least three tests at different over consolidation ratios (OCRs) for its calibration. For this purpose, a simple method is also proposed for determining the TSL line explicitly from the total deformation recorded at the end of the thermal cyclic test (on NC sample). In this way, the number of tests is reduced from three to one. Besides, to better predicting the thermomechanical behaviour of saturated soils, the hardening law is calculated independently for both thermal and mechanical loading cases. Finally, the proposed model is compared with existing recent models as well as experimental data from the literature.

摘要

最近在文献中开发的饱和土的新热力学模型很好地捕捉了正常固结 (NC) 土壤的热循环变形，但对于轻度过度固结 (OC) 土壤则不然。为了改进这一点，在 e-ln(p) 平面中提出了基于参考线 (RL) 和热稳定线 (TSL) 的框架。无论应用的热诱导是单调的还是循环的，使用 RL 和 TSL 线概念很容易从它们的 NC 状态预测轻微 OC 土壤的热塑性体积应变。应该注意的是，TSL 已经存在于文献中，但需要在不同的过度固结率 (OCR) 下进行至少三个测试以进行校准。以此目的，还提出了一种简单的方法，用于根据热循环测试结束时记录的总变形（在 NC 样品上）明确确定 TSL 线。通过这种方式，测试的数量从三个减少到一个。此外，为了更好地预测饱和土的热力学行为，硬化定律在热载荷和机械载荷情况下都是独立计算的。最后，将所提出的模型与现有的最新模型以及文献中的实验数据进行了比较。