非饱和土-结构动力响应的2.5维有限元-完美匹配层法  

2.5 Dimensional Finite Element-Perfectly Matched Layer Method for Calculating Dynamic Response of Unsaturated Soil-Structure System

作　　者：狄宏规[1,2] 苏光北 郭慧吉 周顺华[1,2] 于佳永 DI Honggui;SU Guangbei;GUO Huiji;ZHOU Shunhua;YU Jiayong(Key Laboratory of Road and Traffic Engineering of Ministry of Education,Tongji University,Shanghai 201804,China;Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety,Tongji University,Shanghai 201804,China;Technical Center of Shanghai Shentong Metro Group Co.,Ltd.,Shanghai 201103,China)

机构地区：[1]同济大学道路与交通工程教育部重点实验室,上海201804 [2]同济大学上海市轨道交通结构耐久与系统安全重点实验室,上海201804 [3]上海申通地铁集团有限公司技术中心,上海201103

出　　处：《铁道学报》2023年第8期138-146,共9页Journal of the China Railway Society

基　　金：国家自然科学基金(51808405);上海市科技计划项目(20ZR1459900)。

摘　　要：基于非饱和土的实用波动方程,利用双重Fourier变换和Galerkin法,推导u_(b)-p_(l)-p_(g)格式的非饱和土频域-波数域内的2.5维有限元表达式。引入坐标拉伸函数构建完美匹配层单元,提出非饱和地基-结构动力响应的2.5维有限元-完美匹配层法,并验证该算法的可靠性。以某工程地铁隧道并行高铁路基段为研究背景,利用该方法分析隔离桩对地铁减振效果的影响。结果表明:隔离桩能够显著减小地基表面土体的振动响应,且桩径和隔离桩与隧道距离越大,隔离桩的减振效果越好,双排桩的隔振效果要优于单排桩。隔离桩的存在会使得隧道右侧(无隔离桩侧)的土体响应增强,在隔离桩减振设计时应考虑振动放大现象的影响。Based on the practical wave equation of unsaturated soil,the 2.5 dimensional finite element expression of unsaturated soil in the frequency-wavenumber domain in the u_(b)-p_(l)-p_(g) format was derived using double Fourier transformation and Galerkin method.By introducing the coordinate stretching function to construct the perfectly matched layer elements,the 2.5D FE-PML method for calculating the dynamic response of unsaturated soil-structure system was proposed,whose reliability of the developed method was validated against the existing analytical method.Subsequently,this method was used to analyze the influence of isolation piles on the vibration damping effect in a subway tunnel paralleling a high-speed railway subgrade system.The results show that the isolation piles can significantly reduce the vibration response of the ground surface soil.The greater the pile diameter and the greater the distance between the isolation piles and the tunnel,the better the vibration damping effect of the isolation piles.The vibration isolation effect of double-row piles is better than that of single-row piles.The isolation piles will increase the soil response on the right side of the tunnel(the side without isolation piles).The impact of vibration amplification should be considered in the vibration reduction design of isolation piles.

关 键 词：非饱和土 完美匹配层 地铁振动 隔离桩 

分 类 号：U451.3[建筑科学—桥梁与隧道工程]