不同含水率下赤泥改良土的动弹模及阻尼比研究

Study of Dynamic Modulus and Damping Ratio of Loess Solidified by Red Mud under Different Water Content

为研究不同初始含水状态下赤泥改良土的动力学参数,利用GDS动三轴仪对不同含水率下改良土进行了不同频率下的循环加载试验,研究分析了振次、含水率、加载频率对改良土动弹性模量和阻尼比的影响。试验结果表明:动应力幅值一定时,动弹模随振次增加基本无变化,阻尼比随振次增加呈波动变化,且提出并证明了可用第10振次下的动弹模阻尼比值代表各级荷载下的动弹模阻尼比值;动弹模随动应变幅值的增加先增大后减小,并用二次函数对其进行了拟合,阻尼比随动应变的增加先减小后增大;改良土动弹模在其最优含水率处达到最大,较高的含水率使改良土动弹模明显下降;较小应变幅下动弹模随频率增加而减小,较大应变幅时动弹模随频率增加而增大,阻尼比在加载频率较高时较大。

In order to study the kinetic parameters of loess solidified by red mud under different water conditions,the modified soil under different water content was studied by GDS dynamic triaxial instrument at different frequencies. The effects of vibration time,moisture content and loading frequency on the dynamic modulus and damping ratio of modified soil were studied. The experimental results show that the dynamic modulus keeps with the increase of the vibration time,and the damping ratio changes in volatility with the increase of the vibration time under the same dynamic stress amplitude. It is proved that dynamic modulus and damping ratio of tenth times of vibration can be used to represent the dynamic modulus and damping ratio at various levels loads. The dynamic elastic modulus increases then decreases with the increase of dynamic strain amplitude,and is fitted with the quadratic function. Damping ratio decreases first and then increases with dynamic strain. The dynamic modulus reaches the maximum at its optimal moisture content,and the higher water content makes the modified soil elastic modulus decrease obviously. The dynamic modulus decreases with the increase of the frequency at small strain amplitude,and increases with the increase of the frequency when the amplitude is larger. The damping ratio is larger when the loading frequency is high.