冻土粘弹塑性参数的测试方法

Testing Method of Parameters in Viscoelasticity and Plasticity for Frozen Soil

根据已有冻土试验资料,建立描述冻土粘弹塑性特征的本构模型,给出本构参数的确定方法。首先,推导本构模型的微分列式并根据不同加载条件求解微分方程。其次,设计不同加载条件的冻土试验,以测定应力应变曲线,或应力随时间、或应变随时间曲线。然后,根据以等应变率下的试验曲线为例研究讨论了在不同条件下确定本构参数的方法。包括:在等应变率加载条件下,根据应力应变曲线或应力时间曲线确定本构参数;在等应力加载条件下,根据应力应变曲线或应变时间曲线确定本构参数;在应变率为零时,利用松弛曲线确定本构参数;在应力率为零的条件下,利用蠕变曲线确定本构参数。

A viscous elastic-plastic model of frozen soil and the method determining the constitutive parameters of the model have been presented based on the experimental data and curves.First,the constitutive differential equations of the model and the solution to the equations have been derived under different loading conditions.Second,test of samples of frozen soil have been made to obtain the curves of stress-strain,or the curves of stress-time,or the curves of strain-time.Then,the method determining the constitutive parameters of the model has been discussed,which is based on the experimental data and curves.The situations include loading under constant strain rates;loading under constant stress rates;relaxing;creeping.