摘要
采用37φmm铝质分离式Hopkinson压杆试验装置,研究了冻结温度为-8℃、-12℃和-16℃条件下人工冻结黏土在单轴和围压两种受力状态下的冲击破坏特征和强度特性。试验结果表明,当应变率相同时,单轴和围压两种受力状态下人工冻土的最大应力均随冻结温度的降低而增大,表现出较强的温度效应。在高应变率加载条件下,两种受力状态下人工冻土的冲击破坏形态分别呈现出脆性破坏和黏塑性破坏。当冻结温度和冲击气压相同时,两种受力状态下人工冻土表现出明显不同的动力特性,且围压状态下人工冻土最大应力明显高于其在单轴状态下的最大应力,呈现出明显的应力强化特性。
The aluminium split Hopkinson pressure bar （SHPB） apparatus with diameter of 37ram has been a- dopted to study the impact failure characteristic and dynamic strength behaviour of artificial frozen soil in both uniaxial loading state and confining pressure state. The artificial frozen soil is remoulded at freezing temperature of - 8 ℃ , - 12 ℃ and -16℃. The test results show that when the strain rate is fixed, the maximum stress of artificial frozen soil increases with the decrease of freezing temperature in both uniaxial loading state and confining pressure state, which displays a strong temperature effect. Under high strain rate conditions, the failure mode of artificial frozen soil is brittle failure when in uniaxial state and viscoplastieity failure when in confining pressure state. When the freezing temperature and impact pressure are fixed, the dynamic mechanical characteristics of artificial frozen soil in uniaxial loading state and confining pressure state show a significant difference, and the maximum stress of artificial frozen soil in confining pressure state is apparently higher than that in uniaxial loading state, which displays an obvious stress strengthening characteristics.
出处
《地下空间与工程学报》
CSCD
北大核心
2014年第1期26-29,共4页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金资助(50874003)
关键词
人工冻土
冻结黏土
SHPB
破坏特征
围压
artificial frozen soil
frozen clay
SHPB
failure characteristic
confining pressure
