摘要
利用分离式Hopkinson压杆(SHPB),以铝质套筒作为围压装置,分别研究温度为-8、-12、-16℃在不同应变率下的人工冻结黏土围压状态变形特征和轴向动态应力-应变关系。研究结果表明:在围压状态下,冻土呈黏塑性破坏特征;当人工冻结黏土温度为-16℃、平均应变率分别为410、457、525、650、827 s-1时,其最大应力分别为10.76、12.18、14.27、20.24、23.34 MPa,最大应变分别为0.081 7、0.097 2、0.105 0、0.131 0和0.166 0,表现出较强应变率效应;-12℃和-16℃时在应变率为457 s-1下的最大应力分别为8.28 MPa和12.18 MPa;当应变率相同时,温度越低,最大应力越大,冻结黏土表现出较强的温度相关性。人工冻土的动力学特性为冻土开挖方法的研究提供依据。
Split Hopkinson pressure bar （SHPB） was adopted to study the deformation behaviors and axial dynamic stress-strain relationship of artificial frozen clay in confining pressure state. Three kinds of artificial frozen clay with frozen temperatures of-8℃,-12℃and-16℃were investigated in SHPB test. And aluminum sleeve was chosen as confining pressure device. The results show that viscoplasticity failure is presented when artificial frozen soil in confining pressure state under high strain rate. When average strain rates are 410 s-1, 457 s-1, 525 s-1, 650 s-1 and 827 s-1, the maximum stresses of artificial frozen soil at-16℃are 10.76 MPa, 12.18 MPa, 14.27 MPa, 20.24 MPa and 23.34 MPa respectively;and the maximum strains of artificial frozen soil at-16℃are 0.081 7, 0.097 2, 0.105 0, 0.131 0 and 0.166 0 respectively. Besides, when average strain rate is 457 s-1, the maximum stress of artificial frozen soil at-12℃is 8.28 MPa;and the maximum stress of artificial frozen soil at-16℃is 12.18 MPa. When the strain rate is the same, the lower the frozen temperature, the larger the maximum stress of artificial frozen soil. Strong temperature correlation could be observed from artificial frozen soil in high strain rate. Research on dynamic mechanical behaviors of artificial frozen clay will provide some supports for frozen soil excavation.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2014年第3期637-640,共4页
Rock and Soil Mechanics
基金
国家自然科学基金资助(No.50874003)
