论文部分内容阅读
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。
By using the split Hopkinson pressure bar (SHPB) and the aluminum sleeve as the confining pressure device, the deformation characteristics of the confined pressure of artificial frozen clay with different strain rates at -8, -12 and -16 ℃ and axial Dynamic stress-strain relationship. The results show that under the confining pressure condition, the frozen soil shows the characteristics of viscoplastic failure. When the temperature of artificial frozen clay is -16 ℃ and the average strain rate is 410, 457, 525, 650, 827 s-1 respectively, the maximum stress Respectively, at 10.76, 12.18, 14.27, 20.24, 23.34 MPa and maximum strain of 0.081 7, 0.097, 2,0.105 0, 0.131 0 and 0.166 0 respectively, showing a strong strain rate effect; at -12 ℃ and -16 ℃, The maximum stress at 457 s-1 is 8.28 MPa and 12.18 MPa, respectively. When the strain rate is the same, the lower the temperature and the larger the maximum stress, the stronger the temperature dependence of the frozen clay. The dynamic characteristics of artificial frozen soil provide the basis for the research of frozen soil excavation method.