一个统一描述饱和-非饱和土温度效应的热-弹塑性本构模型

A unified thermo elastoplastic constitutive model describing the temperature effect of saturated and unsaturated soils

地热资源开发与利用及核废料地质处理等诸多岩土工程问题,都需要考虑温度对饱和土和非饱和土应力、应变特性的影响。为了综合反映温度和吸力对土的先期固结压力的影响,提出了不同温度下土的先期固结压力的表达式。将此表达式与黏土–砂土统一状态参数模型屈服面相结合,考虑了温度和吸力对正常固结线及临界状态线的影响,提出了一个统一描述饱和–非饱和土温度效应的热–弹塑性本构模型。该模型分为饱和段(吸力小于某一温度下的进气值或排气值)与非饱和段(吸力大于某一温度下的进气值或排气值)。模型预测与试验数据的对比表明,该模型能够较好地定量描述不同温度下饱和土和非饱和土的应力、应变特性。

Many geotechnical problems, such as development and utilization of geothermal resources and nuclear waste disposal, need to consider the effect of temperature on the stress and strain properties of saturated and unsaturated soils. To consider the effects of temperature and suction on the preconsolidation stress change for soils, expressions of preconsolidation stress for soils at different temperatures are first introduced. After that, combining the expression with the yield surface of unified state parameter model for clay and sand, considering the influence of temperature and suction on the normal consolidation line and critical state line, a unified thermo elastoplastic constitutive model describing the temperature effect of saturated and unsaturated soils is proposed. The proposed constitutive model is divided into saturated part(suction less than the air entry value or bubbling pressure at certain temperature) and unsaturated part(suction more than the air entry value or bubbling pressure at certain temperature). The comparisons between the model predictions and experimental data indicate that the proposed model can quantitatively predict the stress and strain properties of saturated and unsaturated soils at different temperatures.