循环荷载下冻土振陷增长规律试验研究
发布时间：2018-10-11 08:25
【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。
[Abstract]:Through the constant amplitude cyclic load test of a new low temperature dynamic triaxial instrument, the residual strain law of frozen soil during freezing period, including temperature, is studied in order to conform to the objective reality of confining pressure, dynamic stress amplitude and consolidation and freezing mode. The influence of the magnitude and number of loads on the residual strain of frozen soil. The results show that the residual strain of frozen soil increases continuously with the increase of load vibration times and decreases with the decrease of temperature, and the residual strain growth pattern of frozen soil is that the residual strain increases rapidly at the beginning stage, and then slowly increases gradually. When the dynamic stress exceeds the critical failure stress, the residual strain of soil specimen increases rapidly and reaches failure, and the failure stress of low temperature frozen soil is much higher than that of normal temperature. Low-temperature -5 鈩，
本文编号：2263507
[Abstract]:Through the constant amplitude cyclic load test of a new low temperature dynamic triaxial instrument, the residual strain law of frozen soil during freezing period, including temperature, is studied in order to conform to the objective reality of confining pressure, dynamic stress amplitude and consolidation and freezing mode. The influence of the magnitude and number of loads on the residual strain of frozen soil. The results show that the residual strain of frozen soil increases continuously with the increase of load vibration times and decreases with the decrease of temperature, and the residual strain growth pattern of frozen soil is that the residual strain increases rapidly at the beginning stage, and then slowly increases gradually. When the dynamic stress exceeds the critical failure stress, the residual strain of soil specimen increases rapidly and reaches failure, and the failure stress of low temperature frozen soil is much higher than that of normal temperature. Low-temperature -5 鈩，
本文编号：2263507
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