无砟轨道路基翻浆机理及基床排水优化设计  

Mechanism of frost boiling and optimization of drainage design in ballastless track subgrade bed

作　　者：刘孟适 罗强[1] 郭建湖[2] 吴鹏 梁多伟 LIU Mengshi;LUO Qiang;GUO Jianhu;WU Peng;LIANG Duowei(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Siyuan Survey and Design Group Co.,Ltd,Wuhan 430063,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《北京交通大学学报》2019年第3期16-25,共10页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：国家重点基础研究发展计划(973计划)(2013CB036204);铁四院科技研究开发计划(2015K26-1)~~

摘　　要：多雨地区无砟轨道基床翻浆是一种新的路基病害现象.通过开展室内单元填土动态模型试验,明确了基床翻浆的形成机理;针对现行无砟轨道基床排水措施,进行了基床入渗排水能力检算;基于基床表层典型排水断面最大渗出流量大于路基面最大入渗流量的原则,采用高透水材料替换路肩封闭层下级配碎石,并设置路肩排水盲沟的手段,提出了“透水式路肩”基床排水优化设计方法.研究结果表明:底座与路基面出现离缝、离缝积水、列车动荷载作用是引发无砟轨道基床翻浆的3个基本要素;现有设置于基床表层底部的防渗排水层排水性能无法满足细粒含量小于7%的级配碎石入渗能力;“透水式路肩”能够有效提高基床的排水能力,防止路基面离缝长时间积水,以避免翻浆病害的产生,所增设透水材料的渗透系数和置换深度主要由级配碎石渗透系数、基床表层底部防渗排水层导水率和横坡坡度决定.Frost boiling is a new phenomenon of ballastless track subgrade disease in rainy regions.With the help of dynamic element filler model test,the formation mechanism of subgrade frost boiling is ascertained.According to current subgrade drainage measures of ballastless track,the capacity of infiltration and drainage of subgrade is checked.Based on the principle that the maximum exudation discharge of typical drainage section should exceed the maximum infiltration discharge in surface layer of subgrade bed,an optimization drainage design method of subgrade bed called "permeable subgrade shoulder"is proposed,by applying high permeability material to substitute graded crushed stone under waterproof layer of subgrade shoulder and setting blind drain.The researches indicate that gap formation and ponding between foundation plate and formation surface,train load action are the basic factors to trigger frost boiling of ballastless track subgrade.The current drain capability,which is determined bydrainable-waterproof layer at the surface of bottom layer of subgrade bed,can’t satisfy the infiltration capacity of graded crushed stone whose fines content is less than 7%."Permeable subgrade shoulder"effectively improves exudation discharge of subgrade bed and prevents formation surface gap from longterm ponding,so that can avoid frost boiling.The permeability coefficient and substitution depth of additional permeability material in subgrade shoulder are mainly influenced by graded crushed stone permeability,transmissivity of drainable-waterproof layer,crown slope of bottom layer of subgrade bed.

关 键 词：无砟轨道 翻浆冒泥 模型试验 入渗排水 优化设计 

分 类 号：U213.1[交通运输工程—道路与铁道工程]