降雨入渗下铁路路基含水率分布及影响分析  

Variation in Water Content and Influences on RailTrack Embankment Subject to Rainfall Infiltration

作　　者：肖源杰[1] 陈刘欣 卢小永 王萌[1] 李文奇 陈晓斌[1] 叶新宇[1] XIAO Yuanjie;CHEN Liuxin;LU Xiaoyong;WANG Meng;LI Wenqi;CHEN Xiaobin;YE Xinyu(MOE Key Laboratory of Engineering Structures of Heavy HaulRailway,Central South University,Changsha,Hunan 410075,China;Monash University,Melbourne,Victoria 3800,Australia;Science and Technology Research Institute,Daqin Railway Co.Ltd,Taiyuan,Shanxi 030013,China)

机构地区：[1]中南大学重载铁路工程结构教育部重点实验室,长沙410075 [2]莫纳什大学,墨尔本3800 [3]大秦铁路股份有限公司科学技术研究所,太原030013

出　　处：《铁道工程学报》2020年第7期7-12,共6页Journal of Railway Engineering Society

基　　金：国家重点研发计划(2017YFB1201204);国家自然科学基金资助项目(51878673,U1734208,U1934209,51808577);湖南省自然科学基金资助项目(2018JJ3658);中国铁道科学研究院科技研究开发计划重大课题(2019YJ026);大秦铁路股份有限公司重载技术升级专项计划(A2019G03)。

摘　　要：研究目的:为深入分析降雨入渗诱发铁路路基病害的内在机制,采用非饱和渗流数值计算理论,考虑基床填料回弹模量和累积塑性应变的含水率敏感性,建立二维有限元分析模型,研究不同降雨强度下路基降雨入渗深度、饱和区、含水率、回弹模量和累积塑性应变的变化及分布规律.研究结论:(1)降雨入渗条件下水分在基床表层内迁移,难以透入基床底层;(2)降雨入渗导致基床表层平均竖向回弹模量值降低,基床底层平均竖向回弹模量值影响较小;(3)当日降雨量增长到25 mm时,基床表层和基床底层交界面出现水分富集,易软化而引发基床局部塌陷、不均匀沉降和层间接触面剪切破坏等路基病害;(4)通过研究得出基床表层裂缝渗水区域和基床底层底部是路基排水及养护维修重点;(5)本文成果可为铁路路基防排水设计和养护维修决策提供参考.Research purposes:In order to better understand internal mechanism of railway subgrade disease induced by rainfall infiltration,the finite element model of typicalHSR track substructure was developed based on the unsaturated flow theory and consideration of moisture-sensitive characteristics of resilient modulus and accumulated plastic strain behavior.The influencing depth of infiltration,the saturated zone,water content,resilient modulus,and accumulated plastic strain,and their temporal-spatial variations with different rainfall intensity levels were analyzed.Research conclusions;(1)The rainfall infiltration mainly affects the top embankment with rainwater hardly migrating into the bottom embankment or deeper depth.(2)Rainfall infiltration leads to the decrease of average vertical resilient modulus for top embankment but insignificant change for bottom embankment.(3)When the daily rainfall intensity increases to 25 mm,the saturated areas within the top embankment become considerable and inter-connected with water pockets formed at the interface of embankment layers,which may cause local collapse,differential settlement,or shear failure along the interface.(4)The priority areas of subsurface drainage design and maintenance are surface cracks of top embankment and bottom surface of lower embankment.(5)The research findings could provide references for the design and maintenance decision of railway subgrade waterproof and drainage.

关 键 词：路基基床 降雨入渗 回弹模量 累积塑性应变 

分 类 号：U216.41[交通运输工程—道路与铁道工程]