摘要
饱和砂土基于相变状态的改进本构模型能较好地描述砂土不排水情况下的应力-应变关系。通过改进模型中相变状态参量的计算方法,将e-lgp￠表达式加以改进,通过详细的阐述,提出e_(pt)-lgp的关系式,并通过三轴压缩试验的数据对提出的关系式加以验证。应用新的关系式计算不排水条件下试样的相变孔隙比e_(pt),进而计算出模型中的相变状态参量。改进后的不排水本构模型的计算结果与不排水三轴压缩的试验结果能较好地吻合,即验证了本构模型的有效性,也验证了e_(pt)-lgp关系式的合理性,使原有的边界面本构模型更好地描述不排水的情况下、不同密度和围压状态下饱和砂土的力学行为。
A modified constitutive model of saturated sands based on the phase transformation state can well describe stress-strain relationship of sands under undrained conditions. By improving the calculation method of the phase transformation state parameter in the model, an expression for e-lgp＇ is modified. Through detailed elaboration, a relationship for ept-lgp is proposed and is verified through triaxial compression test data. The proposed new relationship is used to calculate the phase transformation void ratio ept of the sample under undrained condition, and then the phase transformation state parameters are calculated in the model. These calculated results from the improved undrained constitutive model fit well with undrained triaxial compression test results, verifying the effectiveness of the constitutive model and the rationality of the relationship for ept-lgp. Moreover the original boundary surface constitutive model can better describe the mechanical behavior of undrained, saturated sands under varying density and confining pressure conditions.
出处
《工程力学》
EI
CSCD
北大核心
2015年第12期68-76,共9页
Engineering Mechanics
基金
国家自然科学基金项目(51478135
51208031)
中央高校基本科研业务费专项资金项目(2015JBM068
2014JBZ013)
关键词
饱和砂土
不排水
相变状态
相变孔隙比
本构模型
ept-lgp
saturated sands
undrained
phase transformation state
phase transformation void ratio
constitutive model
ept-lgp
