2.5维有限元分析高铁荷载下准饱和横观各向同性地基振动特性  

2.5D finite element analysis for vibration characteristics of quasi-saturatedtransversely isotropic foundation under high-speed railway load

作　　者：高广运[1,2] 耿建龙 张其唯 张璐璐 司志鹏 GAO Guangyun;GENG Jianlong;ZHANG Qiwei;ZHANG Lulu;SI Zhipeng(Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;Fiscal Invested Construction Project Management Center of Guangzhou Development District,Guangzhou 510700,China;China Railway Design Corporation,Tianjin 300142,China)

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学土木工程学院,上海200092 [3]广州开发区财政投资建设项目管理中心,广州510700 [4]中国铁路设计集团有限公司,天津300142

出　　处：《振动与冲击》2023年第15期298-308,共11页Journal of Vibration and Shock

基　　金：国家自然科学基金(42277130;51978510)。

摘　　要：为分析高铁荷载下准饱和横观各向同性地基振动特性,推导了准饱和横观各向同性地基2.5维有限元控制方程,建立了列车-轨道-准饱和横观各向同性地基2.5维有限元模型,对比研究了不同车速下饱和与准饱和横观各向同性地基的振动特性,分析了准饱和横观各向同性地基土体参数对振动特性的影响。研究结果表明,准饱和横观各向同性地基表面产生的向上和向下位移均大于饱和地基。不同车速下准饱和地基振动位移均大于饱和地基,但超静孔压远小于饱和地基;车速越高,饱和与准饱和地基表面振动位移越大而衰减越慢,超静孔压越大且衰减越快,轨道中心处准饱和与饱和地基位移相差越大。准饱和地基竖向振动位移和超静孔压随水平弹性模量和垂直弹性模量的增加而减小,随水平泊松比增加而增大,随垂直泊松比增加而减小,随垂直剪切模量增加而减小。垂直弹性模量较水平弹性模量对地面竖向振动位移影响更大。与水平泊松比相比,垂直泊松比对准饱和横观各向同性地基竖向振动位移峰值和超静孔压影响更大。Here,to analyze vibration characteristics of quasi-saturated transversely isotropic foundation under high-speed railway load,a 2.5D finite element control equation for the foundation was derived to establish the 2.5D finite element dynamic model for the train-rail-foundation system,and contrastively study vibration characteristics of the foundation under different train speeds.Effects of soil parameters on vibration characteristics of quasi-saturated transversely isotropic foundation were analyzed.The results showed that upward and downward displacements generated by surface of quasi-saturated transversely isotropic foundation are larger than those of saturated foundation;under different train speeds,vibration displacements of quasi-saturated foundation are larger than those of saturated foundation,but the former’s excess pore pressure is much smaller than the latter’s;the higher the train speed,the larger the surface vibration displacements of saturated and quasi-saturated foundations and the slower the attenuations of them;the larger the excess pore pressure and the faster the attenuation of it,the larger the difference between displacements of quasi-saturated and saturated foundations at rail center;vertical vibration displacement and excess pore pressure of quasi-saturated foundation decrease with increase in horizontal elastic modulus and vertical one,increase with increase in horizontal Poisson’s ratio,decrease with increase in vertical Poisson’s ratio,and decrease with increase in vertical shear modulus;quasi-saturated foundation’s vertical elastic modulus has a larger impact on ground vertical vibration displacement than its horizontal elastic modulus does;compared to horizontal Poisson’s ratio,quasi-saturated foundation’s vertical Poisson’s ratio has a larger impact on its peak vertical vibration displacement and excess pore pressure.

关 键 词：高铁 准饱和横观各向同性地基 2.5维有限元模型 地面振动 土体参数 

分 类 号：TU43[建筑科学—岩土工程]