加载频率对反滤料动变形特性影响的试验及细观数值模拟研究

在动三轴试验过程中,加载频率对动模量和阻尼比的影响目前还没有定论。基于室内动三轴试验结果,采用二维颗粒流程序PFC2D模拟了筑坝反滤料在不同加载频率(f=1.0、0.5、0.1、0.05 Hz)条件下的室内动三轴试验。数值模拟结果与试验结果基本吻合,试验结果表明,(1)当f≥0.1 Hz时,频率对动模量和阻尼比的影响可以忽略;当f<0.1 Hz时,模量在小应变情况下会有所降低,但随着应变的增大会趋于一致。(2)阻尼比在f=0.05 Hz时波动比较大,但与其他频率条件下的阻尼比相比都在一个较小的区域内,可以认为频率对阻尼比基本没有影响。

Study of test and mesomechanical simulation of influence of vibration frequency on dynamic deformation property of inverted filler

The influence of loading frequency on dynamic modulus and damping ratio has been inconclusive in dynamic triaxial test. Therefore PFC2D is adopted to simulate dynamic triaxial test of the inverted filler of earth-rockfill dam in different vibration frequencies. The simulated results have tallied in general with those of the test, which shows the influence of frequency on dynamic modulus and damping ratio can be ignored when the frequency is not higher than 0.1 Hz; and that the modulus will decrease in small strain but it will begin to converge as the strain become larger when the frequency is lower than 0.1 Hz. Though the damping ratio has a little fluctuated at 0.05 Hz, it is still in a narrow range when compared with that in other frequencies; so it can be believed that the influence can be ignored.