基于虚土桩模型,运用Laplace积分变换和阻抗函数递推方法研究了纵向任意激振力作用下沉渣特性对成层土中嵌岩桩桩顶动力响应的影响.将桩端沉渣模拟为虚土桩,对桩侧土采用平面应变模型,并考虑其成层特性,结合初始条件和桩顶及沉渣底部的边界条件,求得在桩顶任意激振力作用下,考虑沉渣影响的桩顶频域响应解析解及时域响应半解析解.基于理论解,分析了沉渣特性对桩顶动力响应的影响,并将理论计算结果与工程桩低应变反射波法实测曲线进行了拟合对比,结果表明,基于虚土桩模型的理论解能较好地反演出沉渣特性对桩顶动力响应的影响.%Based on virtual soil pile model, the influence of sediment characteristics on the dynamic response of rock-socketed pile in layered soil was presented by means of Laplace integral transform technique and impedance function transfer method when the top of rock-socketed pile was undergoing arbitrary longitudinal exciting force. The sediment was modeled as virtual soil pile model whose cross-section area was same as the pile and the surrounding layered soils were described with the plane strain model. By using the initial conditions and boundary conditions of the soil-pile system, the analytical solutions for the longitudinal dynamic response of the pile top in frequency domain and the relevant semi-analytical solutions in time domain were obtained at condition of arbitrary excitation on the pile top. Based on the presented solutions, the influence of sediment characteristics on the dynamic response at the pile top was investigated. By using the parametric inversion method, it is proved that these solutions based on virtual soil pile model have sufficient accuracy for the theoretical curves were in good agreement with those obtained by the low-strain reflected wave method from the field measurement.
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