不同频率影响下结构性软黏土动力特性试验研究
Experimental study on dynamic characteristics of structural soft clay under different vibration frequencies
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摘要: 为研究频率对结构性软黏土动力特性的影响,以天津滨海新区结构性海积软土为试验材料,基于两种波形,进行了一系列动三轴试验,研究不同振动频率作用下结构性软黏土应力-应变关系、动力塑性累积应变以及孔压特性。试验结果表明,总体上振动频率越低,土体的软化程度越高,土体产生的变形越大,累积应变增速快最终值大,相同条件方波作用下的动应力应变软化程度高于正弦波。频率对孔压有影响,在相同振次下,孔压随频率的增大而减小。振幅对于孔压变化的影响表现为低幅值上升速度快,数值也大于高幅值作用下的孔压值,有明显的高幅滞后现象。Abstract: To study the influence of frequency on the dynamic characteristics of structural soft clay, a series of dynamic triaxial tests based on the two kinds of waveforms and different vibration frequencies are performed. The results show that when the vibration frequency is smaller and the deformation of the soil is larger, the deformation of the soft clay and permanent strain will be larger. Under the same conditions, the dynamic stress-strain softening degree of the square wave is higher than that of the sine wave. Under the same number of vibration, the pore pressure decreases with the increasing frequency. The effect of amplitude on the change of pore pressure is that the pore pressure increases fast and the stable value is larger when the amplitude is low.