三维波动土中带承台单桩的纵向振动特性研究  

Longitudinal vibration of single pile with cushion cap in three-dimensional layered surrounding soil

作　　者：王奎华[1,2] 郭海超 高柳[1,2] 肖偲[1,2] 

机构地区：[1]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058 [2]浙江大学滨海与城市岩土工程研究中心,浙江杭州310058

出　　处：《岩石力学与工程学报》2018年第2期497-505,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51378464;51579217)~~

摘　　要：基于考虑三维波动的桩周土模型和虚土桩法,研究三维波动土中承台–桩–土相互作用的纵向振动特性。首先,根据桩周土和虚土桩的成层性将桩土系统划分为若干层,运用阻抗函数递推法得到桩顶的位移阻抗函数,进而得到承台–桩系统的位移响应的频域解析解,利用Laplace逆变换得到承台–桩系统位移时域响应的半解析解。然后通过参数分析,研究桩周土的剪切波速、黏性阻尼系数和泊松比对承台–桩系统纵向振动的影响;同时研究多层土中硬质夹层剪切波速,厚度和深度对承台–桩系统纵向振动的影响。研究结果表明,相比于桩侧土黏性阻尼和泊松比,桩侧土剪切波速对承台–桩系统纵向振动影响更大;上层土对承台–桩系统纵向振动的影响大于下层土。最后将理论计算结果与现场实测曲线进行对比,证明该三维波动土中承台–桩–土相互作用的模型较为合理。The longitudinal vibration of single pile with cushion cap in three-dimensional soil was derived according to three-dimension soil modeling around pile and fictitious soil pile.Firstly,the cap-pile-soil system was discretized into the finite segments considering the stratification of the surrounding soil and fictitious soil pile.Then the impedance function of displacement at the top of pile was obtained with the method of impedance function transfer.The analytical solutions of displacement of the system of cushion cap and pile in frequency domain were obtained.The semi-analytical solutions of displacement of the system of cushion cap and pile in time domain were obtained with Laplace transform.The parameters of the surrounding soil including the shear wave velocity,damping coefficient and Poisson′s ratio were analyzed.Meanwhile,the parameters including the shear wave velocity,depth and thickness of the hard interlayer in the multilayered soil were analyzed.Compared with the damping coefficient and Poisson′s ratio of surrounding soil,the shear wave velocity in surrounding soil has the greater effect on the longitudinal vibration of cap-pile system.The upper soil layer affects the longitudinal vibration of cap-pile system more than the lower soil layer.Finally,the theoretical calculated results were compared with the measured data from field monitoring,which confirmed the sensibleness of the three-dimension soil model of the pile with cushion cap.

关 键 词：桩基础 三维波动土 承台 成层土 纵向振动 

分 类 号：TU473[建筑科学—结构工程]