第一作者吴文兵男，博士，副教授，1988年生

黏弹性地基中基于虚土桩模型的桩顶纵向振动阻抗研究

吴文兵1，蒋国盛1，邓国栋2，谢邦华1

(1.中国地质大学(武汉)工程学院，武汉430074；2.中南大学土木工程学院，长沙410075)

摘要：基于虚土桩模型，对均质黏弹性地基中桩土纵向耦合振动问题进行了研究。首先，假定桩侧土为各向同性的线性黏弹性材料，并考虑土体的竖向波动效应，结合Euler-Bernoulli杆件理论，建立了桩土纵向耦合振动的定解问题；其次，采用分离变量法求解桩侧土纵向振动的控制方程，得到了桩侧土与桩身接触面上的剪切动刚度，将所得的剪切动刚度代入到桩身振动控制方程，采用Laplace变换技术，进一步求得了任意荷载作用下桩顶纵向振动阻抗的解析解。基于所得解，详细讨论了不同桩身设计参数时桩端土厚度对桩顶纵向振动阻抗的影响。最后，将虚土桩模型与其他桩端土支承模型进行了对比研究，结果表明，对虚土桩模型选用合适的材料参数和桩端土厚度，其得到的桩端支承复刚度值介于现有多种模型的计算值之间。

关键词：虚土桩模型；纵向振动阻抗；黏弹性地基；竖向波动效应；Laplace变换；解析解

基金项目：国家自然科学基金青年项目(51309207)；中国博士后科学基金特别资助项目(2013T60759)；中国博士后科学基金面上项目(2012M521495);中央高校基本科研业务贵专项资金-摇篮计划(CUGL150411)

收稿日期：2013-10-21修改稿收到日期：2014-04-16

中图分类号:TU435

文献标志码：A

DOI:10.13465/j.cnki.jvs.2015.07.030

Abstract:Based on fictitious soil pile model, the vertical dynamic response of pile embedded in homogeneous viscoelastic soil was investigated. Assuming the surrounding soil of pile to be isotropic viscoelastic material and considering its vertical wave effect, the definite problem of soil-pile system subjected to arbitrary dynamic force was established based on the Euler-Bernoulli rod theory. The shear dynamic stiffness at the interface of soil and pile was derived by means of separation of variables to solve the governing equation of surrounding soil. Substituting the shear dynamic stiffness acquired into the governing equation of pile, the analytical solution of vertical dynamic impedance was deduced by virtue of Laplace transform technique. Based on the obtained solution, the influence of depth of pile end soil on the vertical dynamic impedance was studied in detail with different design parameters of pile. Constrast analysis was made between the fictitious soil pile model and other pile end soil supporting models. It is shown that the complex supporting stiffness calculated by fictitious soil pile model is in the middle of the supporting stiffnesses calculated by other existing models if adopting appropriate material parameters and proper depth of pile end soil in the fictitious soil pile model.

Vertical dynamic impedance of pile embedded in viscoelastic soil based on fictitious soil pile model

WUWen-bing1,JIANGGuo-sheng1,DENGGuo-dong2,XIEBang-hua1(1. Engineering Faculty, China University of Geosciences, Wuhan, Hubei 430074, China; 2. School of Civil Engineering, Central South University, Changsha, Hunan 410075, China)

Key words:fictitious soil pile model；vertical dynamic impedance；viscoelastic soil；vertical wave effect；Laplace transform；analytical solution

桩与土体的动力相互作用问题包括两个方面，一是桩与桩侧土的动力相互作用，二是桩与桩端土的动力相互作用。……