【摘要】 为探讨动力荷载作用下桩身的压屈稳定性,以m法考虑桩周土的横向抗力,利用能量法和Hamilton原理,基于桩顶自由、桩端嵌固边界条件下的高承台单桩基础动力稳定分析模型,建立了竖向简谐荷载下桩身动力稳定的Mathieu方程。采用三角级数求解,获得了基桩的动力不稳定区域。由此进行的参数对比分析表明,随桩土体系中桩身长径比的增加、埋置率的减小、自由长度的增加及桩周土质越趋软弱,桩身动力不稳定区域将增大,而固定荷载P0的影响则较小,这一影响规律与工程实际吻合较好。更多还原

【Abstract】 To discuss the buckling stability of pile under dynamic loads,m method was used with consideration of the lateral resistance of subsoil,and energy method and Hamilton principle were adopted to establish the Mathieu equation of dynamic stability of pile under harmonic vertical loads based on the dynamic stability analysis model for foundation of single pile with high-rise cap under the boundary conditions of free pile top and fixed pile toe.The trigonometric series was introduced to solve the equation with the dynamic unstable regions of pile obtained.A comparative parameter analysis shows that with the increasing of slenderness ratio and free length,and the decreasing of embedded rate and subsoil strength in the pile-soil system,the dynamic unstable regions of the pile shaft will increase,while the influence of magnitude of fixed load P0 will be much smaller,which are in good agreement with the engineering practice.更多还原