【摘要】 基于Rayleigh-Love杆模型,研究考虑横向惯性效应时成层土中楔形桩的纵向振动问题。首先,根据桩周土的成层性并考虑楔形桩的变截面特性,将桩土系统沿纵向划分为有限个微元段。然后,运用Laplace变换技术和阻抗函数递推方法,在平面应变条件下推导得到成层土中楔形桩纵向振动时桩顶复阻抗的解析解。最后,采用参数研究方法,在低频范围内分析楔形桩设计参数对桩顶复阻抗的影响,并将同体积时的楔形桩与均匀截面桩的桩顶复阻抗进行对比。结果表明:(1)楔形桩其他设计参数不变时,动阻尼随着楔角的增大而增大,动刚度也随着楔角的增大而增大,但增大的幅度会随着频率的增大而逐渐减小;(2)楔形桩其他设计参数不变时,动刚度随着桩长的增大而减小,动阻尼随着桩长的增大而增大;(3)对等体积的楔形桩与均匀截面桩,当桩长相同时,楔角越大,动刚度越小,动阻尼越大;当桩端截面积相同时,楔角越大,动刚度越大,动阻尼先增大再减小。更多还原

【Abstract】 Based on Rayleigh-Love rode model,the longitudinal vibration of tapered pile embedded in layered soil is theoretically investigated by considering lateral inertial effect of tapered pile.At first,considering stratification of the surrounding soil and variable cross-section of the tapered pile,the pile-soil system is discretized into finite segments.Then,by virtue of Laplace technique and impedance function transfer method,the analytical solution of complex impedance of tapered pile under longitudinal exciting force is derived.Finally,by means of parametric study method,the influence of the design parameters of tapered pile on complex impedance at the pile head is investigated within the low frequency range,and the complex impedance of tapered pile is compared with that of uniform cross-section pile with same volume.The results show that:(1) When other design parameters of tapered pile remain unchanged,dynamic damping increases as the cone-angle increases,dynamic stiffness also increases as the cone-angle increases,but the increase magnitude decreases gradually as the frequency increases;(2) When other design parameters of tapered pile remain unchanged,dynamic stiffness decreases as the cone-angle increases,and dynamic damping increases as the cone-angle increases;(3) When the volume and length of tapered pile are the same as that of uniform cross-section pile,dynamic stiffness decreases as the cone-angle increases,and dynamic damping increases as the cone-angle increases.When the volume and radius at the pile tip of tapered pile are the same as that of uniform cross-section pile,dynamic stiffness increases as the cone-angle of tapered pile increases,and dynamic damping increases as the cone-angle increases within a small range of cone-angle.更多还原