关键词: 人工冻土, 冻结黏土, 分离式Hopkinson压杆（SHPB）, 试验, 围压状态, 应变率效应, 温度效应

Abstract: 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.

Key words: artificial frozen soil, frozen clay, split Hopkinson pressure bar (SHPB), test, confining pressure, strain rate effect, temperature effect