冻土桩基完整性检测的影响因素

依据应力波反射法的基本理论,通过室内冻土三轴试验得到应力-应变曲线,并计算得到土体在不同温度下的弹性模量,然后利用ANSYS软件建立桩土有限元模型。将室内试验所得土体参数代入数值模拟,分别得到三种工况下桩顶节点的速度波曲线。结果表明,完整桩只在桩底处产生反射波,且与入射波的相位相同。当桩周为黄土,沿桩身传播的速度波入射波与反射波波峰值均高于桩周为冻土的;随着桩周冻土温度的降低,整个波形的衰减趋势越加明显。因此,土体弹性模量对桩基完整性检测有重要影响。

Factors influencing integrity inspection of pile foundation in frozen soil

Based on the basic theory of stress wave reflection method, this article Obtains the stress-strain curve through indoor frozen soil triaxial test, calculates the elastic modulus of the soil at different temperatures, uses ANSYS software to establish a finite element model of pile-soil. Substituting the soil parameters obtained from the indoor test into the numerical simulation, the velocity wave curves of the pile top nodes under three working conditions are obtained respectively. The results show that the complete pile only produces reflected wave at the bottom of the pile and the phase is the same as incident wave. When the pile circumference is loess, the peaks of the incident wave and the reflected wave of the velocity wave propagating along the pile are higher than that of the frozen soil around the pile. As the temperature of the frozen soil around the pile decreases, the attenuation trend of the entire waveform becomes more obvious. Therefore, the elastic modulus of soil has an important influence on the integrity detection of pile foundation.