Research data on Verification of Unified Yield Surface SFG Model Considering Temperature Influence

In landfill foundation treatment, high-level radioactive waste disposal, geothermal resources development and utilization and other engineering construction practice, there is a large amount of unsaturated soil. When unsaturated soil is affected by sunlight, geothermal, nuclear waste, biochemical reaction and other thermal radiation, it will accelerate the settlement and deformation of soil temperature. The building structure based on unsaturated soil will also be affected, so it is of great significance to study the influence of temperature on the stress and deformation of unsaturated soil. In this paper, by extending the SFG model of unified yield surface to consider the influence of temperature change on unified yield surface, a yield surface constitutive model which can reflect temperature-suction-stress at the same time is proposed.In order to verify the applicability of the model, triaxial tests on Jiangxi laterite at different temperatures are carried out to determine the parameters needed for model calculation. The model fitting results are obtained by using the test parameters and compared with the test results. With reference to the experimental data of remolded clay used in the literature by Uchaipichat et al, the model was fitted and analyzed. The results show that the unified yield surface SFG model considering the effect of temperature can better reflect the stress-strain characteristics of soil during compression rebound, dehumidification and shear, and verify the reliability of the constitutive model to reflect the stress-strain characteristics of soil at different temperatures, thus further enriching the constitutive theory of unsaturated soil under the influence of temperature.在填埋场地基处理、高放废物处置、地热资源开发利用等工程建设实践中，广泛存在大量非饱和土（unsaturated soil）。当非饱和土受日照、地热、核废料、生化反应等热辐射影响时，会加速土体的沉降与温度诱导变形。以非饱和土为地基的建筑结构亦会受到波及，因此研究温度对非饱和土应力与变形的影响具有重要的学术与工程价值。本文将统一屈服面SFG模型进行拓展，考虑温度变化对统一屈服面的影响，提出了一种可同时反映温度-基质吸力（suction）-应力耦合效应的屈服面本构模型。为验证该模型的适用性，针对江西红土开展了不同温度条件下的三轴剪切试验，以确定模型计算所需的参数；利用试验参数得到模型拟合结果，并与试验结果进行对比分析。此外，参照Uchaipichat等学者文献中重塑黏土的试验数据，对该模型进行了拟合与分析。研究结果表明，考虑温度影响的统一屈服面SFG模型能够更好地反映土体在压缩回弹、脱湿及剪切过程中的应力应变特性，验证了该本构模型可准确反映不同温度下土体的应力应变特性，进而进一步丰富了温度影响下非饱和土的本构理论。