Study on uniaxial dynamic mechanical properties and constitutive model of frozen clay
In order to study the failure characteristics of frozen soil under dynamic load,the SHPB test system is used to carry out the uniaxial dynamic impact test of frozen soil with strain rate 300s-1～1 000s-1 and moisture content of 13%～22%,and a constitutive model is established to describe the dynamic response behavior of uniaxial permafrost.The results are as follows:(1)The stress-strain curve can be divided into compaction stage,elastic stage,shaping stage and failure stage,and the stress-strain curve oscillates significantly when the strain rate is higher than 700s-1.(2)The compressive strength and elastic modulus are positively correlated with the strain rate as a whole,but the growth rate of compressive strength slows down or even decreases when the strain rate is higher than 900s-1.The maximum strain is a function of the strain rate,and the moisture content has no effect on the maximum strain.(3)Combining Weibull statistical distribution,D-P criterion and Z-W-T equation and introducing moisture content terms,a viscoelastic constitutive model of frozen soil damage that can consider different moisture cuts is established to verify the reliability of the model(R2>0.90),which provides a certain reference for the design and construction of frozen soil engineering.
SHPB testsingle axis dynamic loadingfrozen soildynamic parametersconstitutive model
NETL
NSTL
万方数据
