中文摘要：

通过新型低温动三轴仪的等幅循环荷载试验,以更为符合客观实际的围压、动应力幅值以及固结和冻结方式,研究了冻土冻结期的残余应变规律,包括了温度、荷载作用大小和次数对冻土的残余应变的影响。结果表明：冻土的残余应变随着荷载振动次数的增加不断增长,随着温度的降低不断减少;冻土的残余应变增长模式表现为开始阶段残余应变增长较快,后逐步缓慢增长,当动应力超过临界破坏应力之后,土试样残余应变迅速增长并达到破坏;低温冻土破坏应力较常温较大提高,低温-5℃提高了20%～25%,低温-10℃提高了45%~50%;冻土大多数荷载情况下处于非破坏状态,在一定次数荷载作用后,不同温度土的残余应变发展近似平行状态,大动应力幅值下的土试样的残余应变对温度更敏感。试验设计克服了以往试验过大固结应力和过大动应力的缺欠,得到的结果应符合客观实际。

英文摘要：

Based on the constant-amplitude load tests by a new low-temperature triaxial device under realistic confining pressure, amplitudes of dynamic stress, consolidation and freezing, the residual strain behavior of frozen soil during frozen period is studied considering the influences caused by temperatures, loading amplitudes and loading cycles. The results show that the residual strain during frozen period increases with the increasing cycles of loading, but decreases with the reducing temperatures. The residual strain developing mode shows that it increases dramatically in the initial loading cycles followed by gradual increase of residual strain with time. When the dynamic stress exceeds a critical stress, the residual strain starts to increase dramatically till failure. The critical stress of frozen soil under low temperatures is larger than that under normal temperatures, with increase of 20%~25% at-5℃ and 45%~50% at-10℃. In most cases, the frozen soils tested do not fail and the residual strains under different temperatures develop nearly parallelly after certain cycles of loading. The residual strain is fairly sensitive to the frozen temperatures at large amplitudes of dynamic stress. The proposed test layout overcomes the previous testing limitations such as over consolidating pressure and over dynamic loading, so that the test results are more consistent with the real conditions.