【摘要】 对-0.5、-1.0、-1.5℃三种温度下的冻土试样进行单轴循环压缩试验,每5秒测试一次试样内部的温度,得到了不同振动频率、动应力幅值下冻土试样内部温度随振动时间变化的曲线。结果表明:在循环荷载作用下冻土内部温度会升高,动应力幅值越大,温升速率越大;在一定动应力幅值范围内,随着振动频率的增大,温升速率增大;温升幅值受土样是否破坏以及达到破坏的时间长短影响,在一定动应力幅值下,适中的某一振动频率下其内部温升幅值最大;冻土试样的破坏受其内部温度升高的影响,如果冻土试样内部温度不断升高,试样最后将会发生破坏;而不会破坏的试样内部温度升高到一定值后保持稳定或开始下降,这是由于试样和所处环境之间的热交换引起的。更多还原

【Abstract】 Uniaxial dynamic compression tests on frozen soil were carried out under different cyclic loadings at-0.5℃,-1.0℃,-1.5℃.The temperature of specimen was measured every 5 second during the compression test.The relation curves between the temperature change of specimen and vibration time at different dynamic stress amplitudes and different frequencies are obtained.The results show that the temperature of the specimen will rise under cyclic loadings.The higher dynamic stress amplitude is,the higher temperature rising rate is.When dynamic stress amplitude is in some range,the higher vibration frequency is,the higher temperature rising rate is.The temperature rising value is influenced by whether the specimen could be damaged or not in the test,and it is also influenced by the length of time coming to damage state of the specimen.When dynamic stress amplitude is in some range,the temperature rising value is the maximum under a moderate frequency.Whether the specimen could be damaged is influenced strongly by the temperature rising value for the specimen.If the temperature of the specimen rises continually,the specimen will be damaged sooner or later.The specimen will remain well if the temperature of specimen can maintain steady or decrease because of the heat exchange between the specimen and its surroundings.更多还原