【摘要】 建立了考虑桩土非完全黏结条件下端承桩在饱和土中竖向振动的模型,将土视为线弹性饱和多孔介质,桩简化为一维弹性杆件。通过引入势函数,采用分离变量法对饱和两相介质动力固结方程解耦,求得桩受任意激振力作用下的桩土耦合系统解析解。计算结果表明,桩土非完全黏结条件下桩振动引起的饱和土中孔压分布略小于完全黏结条件下的,其影响幅度随激振频率的增加而增大,随渗透系数的减小而增加。桩顶的频率和时域响应研究结果表明,桩土接触面条件对桩顶动力响应有显著影响。经分析,增大击发能量使桩土出现非完全黏结状态可以加大有效测桩深度。更多还原

【Abstract】 The vertical vibration of end bearing piles embedded in saturated soil layer is investigated theoretically.The imperfect contact between pile and soil is considered.The pile is simplified as a 1-D elastic staff and the soil is regarded as a linear saturated isotropic porous medium.By using variable separation method the governing differential equations of saturated soil are decoupled by introducing the potential function.Under the assumption of imperfect contact between pile and soil the dynamic response of pile to arbitrary vertical load is obtained.Numerical analysis shows that the pore pressure caused by pile vibration under slippage condition is bigger than that of perfect contact and this effect increases with the increase of frequency as well as the decrease of permeability.Numerical results obtained from frequency domain and time domain also indicate that the contact condition between pile and soil has significant influence on the dynamic response of pile vertical vibration.It is concluded that to increase the impact energy for facilitating the imperfect contact can increase the effective depth of pile dynamic test.更多还原