冻结黏土单轴动态力学特性及本构模型研究
Study on uniaxial dynamic mechanical properties and constitutive model of frozen clay
解北京 1刘天乐 1栾铮 1张景顺 1于瑞星 1武博文1
作者信息
- 1. 中国矿业大学(北京)应急管理与安全工程学院,北京 100083
- 折叠
摘要
为研究动载荷下冻土破坏特性,利用 SHPB试验系统开展应变率 300s-1～1 000s-1、含水率 13%～22%冻土单轴动态冲击试验,并建立本构模型描述单轴冻土动力学响应行为.结果表明:(1)应力-应变曲线可以分为压密阶段、弹性阶段、塑形阶段和破坏阶段,应变率高于 700s-1 时应力-应变曲线出现明显振荡;(2)抗压强度和弹性模量整体上与应变率呈正相关趋势,但应变率高于 900s-1 时抗压强度增长速度减缓甚至负增长.最大应变与应变率呈一次函数关系,含水率对最大应变无影响;(3)结合 Weibull统计分布、D-P准则以及Z-W-T方程并引入含水率项,建立能考虑不同含水率冻土损伤黏弹性本构模型,验证模型可靠性(R2>0.90).为冻土工程设计与施工提供一定参考.
Abstract
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.
关键词
SHPB试验/单轴动态加载/冻土/动力学参数/本构模型Key words
SHPB test/single axis dynamic loading/frozen soil/dynamic parameters/constitutive model引用本文复制引用
基金项目
国家重点研发计划(2019YFC0810800)
国家自然科学基金青年基金(51404277)
中央高校基本科研业务费专项(2022YJSAQ15)
出版年
2024
NETL
NSTL
万方数据