均质土中部分埋入粘弹性桩的瞬态波动响应

基于回传射线矩阵法,得到均质土中部分埋入粘弹性桩在单位脉冲作用下的桩顶速度导纳,然后利用Fourier逆变换和卷积定理得到了在瞬态半正弦激振力作用下的桩顶速度时域响应,与全埋入粘弹性桩作对比,分析桩身材料阻尼、外露桩长、桩侧土阻尼和刚度及桩底土阻尼和刚度对桩顶速度导纳和反射波的影响.结果表明:桩材料阻尼、外露桩长、桩侧土阻尼和桩底土阻尼对桩顶频域及时域速度响应有显著影响;桩侧土刚度和桩底土刚度只对速度导纳曲线的低频部分有影响,且桩底土刚度对导纳曲线的相位和反射波的形状及幅值有显著的影响.

Transient Wave of the Viscous-elastic Pile Embedded Partially in Homogeneous Soil

Based on the method of reverberation-ray matrix, the velocity admittance at the top of the viscous-elastic pile which is embedded partially in homogeneous soil is derived under the excitation of unit delta time force. The time velocity response at the pile top is further obtained by inverse Fourier transform and convolution theorem stimulated by a half-sine impulse. The results are compared against those of the viscous-elastic pile embedded totally in homogeneous soil. The effect of the pile damping, exposed pile length, damping and stiffness of the soil around the pile and under the pile tip on the velocity wave and admittance at the top are further analyzed. It is shown that the velocity admittance and reflected wave are affected significantly by the pile damping, exposed pile length, damping of soil around the pile and under pile tip. Stiffness of soil around the pile and under pile tip have effect on low frequency part of the velocity admittance curve. Stiffness of soil under pile tip have significant effect on the phase of the admittance curve, the shape and amplitude of the reflected wave.