膨胀土地基高速铁路路基变形控制分析  

Analysis of Deformation Control of High-speed Railway Subgrade on Expansive Soil Foundation

作　　者：姚裕春[1] 李安洪[1] 陈伟志[1] 丁选明[2] 崔新壮 YAO Yuchun;LI Anhong;CHEN Weizhi;DING Xuanming;CUI Xinzhuang(China Railway Eryuan Engineering Group Co.Ltd,Chengdu,Sichuan 610031,China;Chongqing University,Chongqing 400044,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031 [2]重庆大学,重庆400044

出　　处：《铁道工程学报》2024年第10期13-17,共5页Journal of Railway Engineering Society

基　　金：中国中铁股份有限公司科技研究开发计划重大课题(2022-重大-02)。

摘　　要：研究目的:膨胀土地基在我国分布广泛,浸水后其强度衰减显著,吸水失水产生的胀缩变形反复,工程危害极大,既有铁路、公路路基病害非常突出,膨胀土边坡稳定、基床翻浆冒泥问题现已基本解决,普速铁路和高速公路路基变形也得到了较好控制,但其变形控制标准为20~30 cm,高速铁路以毫米级变形作为控制标准,在膨胀土地基上修建高速铁路路基必须解决路堑和低路堤的膨胀上拱变形和高路堤的沉降变形两大技术难题。研究结论:(1)天然膨胀土地基浸水后膨胀量明显大于无砟轨道铁路工务养护的限值,路基柔性填筑体对膨胀土的膨胀和收缩变形具有较好的缓冲作用;(2)天然膨胀土地基填筑路基在施工期可完成总沉降的80%以上、复合地基加固处理可达90%以上,超固结膨胀土地基上填筑路基高度不大时,加固地基与天然地基的总沉降量均较小;(3)膨胀土地基路堑及低矮路堤工程宜采用路堤式路堑结构,基床范围全部换填,加强防排水措施,地基宜采用小直径、小间距CFG桩加固,一般路堤对浅层4~6 m进行加固处理,高路堤地基处理按一般土质地基进行沉降计算分析确定;(4)本研究结果可为膨胀土地基高速铁路建设提供有益参考。Research purposes:Expansive soil foundation is widely distributed in China,and its strength decreases significantly after immersion.The swelling and shrinkage deformation caused by water absorption and loss is repeated,and the engineering hazard is extremely high.The existing railway and highway subgrade diseases are very prominent.The problems of expansive soil slope stability and subgrade slurry overflow have been solved.The deformation of ordinary railway and highway subgrade has also been well controlled,but its settlement control standard is 20~30 cm.High-speed railway uses millimeter level deformation as the control standard.The construction of high-speed railway subgrade on an expansive soil foundation must solve two technical problems:the expansion arch deformation of road cuts and low embankments,and the settlement deformation of high embankments.Research conclusions:(1)The expansion amount of natural expansive soil foundation after water immersion is significantly greater than the limit value of ballastless track railway maintenance.The flexible filling body of the roadbed has a good buffering effect on the expansion and contraction deformation of expansive soil.(2)During the construction period,the natural expansive soil foundation filling the roadbed can achieve more than 80%of the total settlement,and the composite foundation reinforcement treatment can exceed 90%.When the filling height on the overconsolidated expansive soil foundation is not high,the total settlement of the reinforced foundation and the natural foundation is relatively small.(3)Embankment-type cutting structure should be adopted for expansive soil foundation and low embankment engineering,with all roadbed areas replaced and drainage measures strengthened.Small diameter and small spacing CFG piles should be used for foundation reinforcement.Shallow layers of 4~6 meters should be reinforced for general embankments,and settlement calculation analysis should be conducted for high embankment foundation treatment based on general soil fo

关 键 词：膨胀土地基 高速铁路 变形特性 变形控制技术 

分 类 号：TU213[建筑科学—建筑设计及理论]