冻结黏土单轴动态加载过程的能量耗散特征
王博1,2,姚昌瑞2,张洪乐3,牛圳2

(1.中国矿业大学 深部岩土力学与地下工程国家重点实验室,江苏 徐州 221116; 2.中国矿业大学 力学与土木工程学院,江苏 徐州 221116; 3.徐州中国矿大岩土工程新技术发展有限公司,江苏 徐州 221008)

人工冻结黏土; SHPB试验; 单轴动态加载; 动力学特性; 能量耗散

Energy dissipation characteristics of frozen clay under uniaxial impact loading
WANG Bo1,2,YAO Changrui1,2,ZHANG Hongle3,NIU Zhen2

(1.State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China; 2.School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China; 3.CUMT Geotechnical Engineering & New Technology Development Co.,Ltd,Xuzhou 221008,China)

artificial frozen clay; SHPB test; uniaxial impact loading; dynamic property; energy dissipation

DOI: 10.15986/j.1006-7930.2021.04.003

备注

为研究动态加载条件下人工冻结黏土的动力学特性,使用SHPB动力学试验系统进行了人工冻结黏土的单轴动态加载试验,分析了不同加载应变率及温度条件下人工冻结黏土的动强度和初始动弹性模量的变化规律,并重点讨论了动态加载过程中试样的能量耗散特征.结果表明:(1)在单轴动态加载条件下,人工冻结黏土的动弹性模量、动强度随应变率的增大或温度的降低而增大,但结果数据在低应变率区有一定波动;(2)随着试样内部塑性变形和裂纹扩展增加,试样弹性应变能密度与耗散应变能密度比值逐渐减小,试样也更容易呈现脆性破坏.以上结果有助于认识人工冻土的冲击破坏能量特征,为人工冻土工程设计与施工提供一定的参考.
In order to study the dynamic property of artificial frozen clay under impact loadings,a series of uniaxial dynamic compression test of artificial frozen clay are conducted by using the SHPB test device. The dynamic strength and initial elastic modulus of the artificial frozen clay are analyzed,and the related energy dissipation characteristic under impact loading are also discussed emphatically. The results show that:(1)under uniaxial impact loading,the dynamic strength and initial elastic modulus of the artificial frozen clay increase as the strain rate increases and the temperature decreases,but the test data has a certain randomness at low strain rate;(2)with the increase of plastic deformation and crack propagation in the specimen,ratio of elastic strain energy density to dissipation strain energy density decreases gradually,and the specimen is also more prone to brittle failure. The above results are conducive to deeply understanding energy dissipation characteristic of artificial frozen clay under impact loading and provide effective reference for the design and construction of the artificial freezing soil project.