机构地区: 湖南大学
出 处: 《土木工程学报》 2005年第12期88-93,共6页
摘 要: 利用传递矩阵法,全面推导层状黏弹性土中考虑轴向力影响的水平抗力桩阻抗,并以此寻求频域动载下的基桩变位及其内力规律,为有效地进行桥梁群桩阻抗理论推导奠定基础。实例计算表明,动力荷载下,桩顶竖向力的引入将增大桩顶的变位幅值,减低土的阻抗作用;由于土的振动阻尼参与,致使基桩的受力状况较静力分析时更为复杂,在不同的频率下,桩身内力可能较单向水平力系作用下的要小。此外,在动力有效长度一定范围内进行的土体加固对减小桩顶动侧移有不同的效果。 The impedance of lateral-resisting pile influenced by axial load is derived by means of a transfer matrix method for layered viscous-elastic soils to obtain the displacements and internal forces of the pile-foundation in frequency-domain, which is helpful to deriving the impedance of pile-groups. The numerical example demonstrates that the displacements are augmented with the introduction of vertical force on pile head, namely, the resisting effect of the soil is reduced. Due to the vibrational damping of soils at various frequencies, the internal forces may be less than that when subjected to uni-directional lateral loads under static conditions. In addition, consolidating the soil within the effective dynamic length has various degrees of effectiveness to reducing the lateral displacements.