不同边界条件下非饱和土地基中的Rayleigh波传播

发布时间：2018-06-13 18:44

本文选题：非饱和土 + Rayleigh波　；参考：《水利学报》2015年11期

【摘要】：地球表面绝大部分土层并非处于完全饱和状态,故采用传统的饱和土两相介质理论进行动力学分析时,计算结果往往与实际情况不符。针对这一客观问题,以非饱和土为研究对象,在三相孔隙介质波动理论的基础上开展了非饱和土体半空间中Rayleigh波的弥散特性研究。分别考虑了两种不同的边界条件:(a)不透水不透气地基边界;(b)透水透气地基边界。根据边界条件及相关的本构关系式,推导出相应Rayleigh波的弥散方程,再通过Newton-Raphson法进行数值求解。最后讨论了在不同边界条件下,非饱和土地基表面附近Rayleigh波的弥散特性受到地基土饱和度、频率以及土体固有渗透系数的影响。计算结果表明:在两种边界条件下Rayleigh波的传播均受到地基土饱和度变化的影响。并且,频率及渗透系数在不同边界条件下对Rayleigh波特性的影响明显不同。
[Abstract]:Most of the soil layer on the earth surface is not completely saturated. Therefore, when the traditional two-phase theory of saturated soil is used for dynamic analysis, the calculated results are often inconsistent with the actual situation. Aiming at this objective problem, the dispersion characteristics of Rayleigh waves in half space of unsaturated soil are studied on the basis of wave theory of three-phase porous media. Two different boundary conditions are considered, respectively. The boundary of impermeable and impermeable foundation is considered. According to the boundary conditions and the related constitutive equations, the dispersion equations of Rayleigh waves are derived and solved numerically by Newton-Raphson method. Finally, under different boundary conditions, the dispersion characteristics of Rayleigh waves near the surface of unsaturated soil are affected by the saturation, frequency and intrinsic permeability of the soil. The results show that the propagation of Rayleigh waves under two boundary conditions is affected by the variation of soil saturation. Moreover, the effects of frequency and permeability coefficient on Rayleigh wave characteristics are obviously different under different boundary conditions.
【作者单位】：南京工业大学岩土工程研究所;浙江大学软弱土与环境土工教育部重点实验室;
【基金】：国家自然科学基金资助项目(41502285,51378258) 江苏省自然科学基金(BK20150952) 江苏省高校自然科学研究项目(14KJB41000)
【分类号】：TU435

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