均质土中半埋入变截面桩的瞬态波动响应

基于回传射线矩阵法,求得单位脉冲作用下均质土中半埋入变截面桩的桩顶速度导纳,然后利用Fourier逆变换和卷积定理得到瞬态半正弦激振力作用下的桩顶时域速度响应。比较半埋入缩颈桩、半埋入扩颈桩与半埋入完整桩的速度导纳和反射波,分析缺陷类型和长度、缺陷埋深和程度对速度导纳和反射波的影响,并进行缩颈-扩颈桩与扩颈-缩颈桩的桩顶速度导纳和反射波曲线的对比。结果表明,桩侧介质变化对桩顶速度导纳和反射波的影响小于桩身缺陷。

Transient wave of the pile with variable sections embedded partially in homogeneous soil

Based on the method of reverberation-ray matrix, the velocity mobility, at the top of defective pile with variable sections embedded partially in homogeneous soil, under unit exciting force, is derived. The time velocity response at pile top is further obtained by inverse Fourier transform and convolution theorem acted by a half-sine impulse. The velocity mobility and reflecting waves of the neck-reduced pile, neck-expanded pile, and perfect pile embedded partially in homogeneous soil are compared. The effect of defective type, defective length, defective location and defective degree on velocity mobility and reflecting wave at the pile top are further analyzed, and the velocity mobility curves and reflecting wave curves of neck-reduced-expanded pile and neck-expanded-reduced pile embedded partially in soil are compared. It is shown that the influence of the medium change around the pile to mobility curves and reflecting wave curves is less than that of the defect of pile.