作　　者： ; ; ; ;

机构地区： 浙江海洋学院

出　　处： 《岩石力学与工程学报》 2006年第z2期4215-4225,共11页

摘　　要： 基于Bishop有效应力公式、单相流固结理论以及阻抗函数递推方法,研究考虑地下水位影响时双层土中桩的纵向振动特性。利用拉氏变换,在频域中求得桩顶复刚度和导纳函数的解析解。利用傅里叶逆变换,得到瞬态半正弦脉冲荷载作用下桩顶速度时域响应的半解析解。通过数值计算,分析地下水位深度变化、上层非饱和土体饱和度变化对桩振动特性的影响。结果表明,地下水位埋深及上层非饱和土体饱和度对桩顶复刚度及导纳有一定的影响,而对延时较短的桩顶速度时域响应影响很小。因此,在桩的完整性测试中可以忽略地下水位的影响。 Based on Bishop′s effective stress formula,one-phase flow consolidation theory,and impedance function recursive method,considering the effect of underground water level,the dynamic response of a pile embedded in two-layer soil and subjected to a vertical load is theoretically investigated.The pile is assumed to be vertical and can be dealt with one-dimensional elastic theory.Because of the existence of the underground water,the soil is divided into two layers.The soil above the underground water level is regarded as unsaturated soil and that below the underground water level is regarded as saturated soil.By using Laplace transform,the analytical solutions for the complex stiffness and admittance function at the pile top are derived in frequency domain.Then,a quasi-analytical solution for the velocity response of the pile subjected to a semi-sine wave exciting force is derived by using Fourier inverse transform.Through numerical calculation,the influences of the major parameters on the response of the pile are analyzed.It is shown that the depth of the underground water level and the saturation degree of the unsaturated soil have certain influences on the admittance and complex stiffness at the pile top,but have negligible influences on the velocity response in time domain at the pile top.Hence,the influence of the underground water level can be negligible in pile integrity test and estimation.

关 键 词： 桩基工程 地下水位 非饱和土 阻抗函数 桩 纵向振动

领　　域： [建筑科学] [建筑科学]