长江科学院院报 ›› 2020, Vol. 37 ›› Issue (5): 133-138.DOI: 10.11988/ckyyb.20190069

• 岩土工程 • 上一篇    下一篇

季节性冻土区铁路路基冻融变形规律

于景飞, 张文月, 李明浩   

  1. 内蒙古科技大学 土木工程学院,内蒙古 包头 014000
  • 收稿日期:2019-01-18 出版日期:2020-05-01 发布日期:2020-06-10
  • 作者简介:于景飞(1973-),男,内蒙古赤峰人,副教授,硕士,主要从事岩土工程研究。E-mail:2998301249@qq.com
  • 基金资助:
    内蒙古自然科学基金项目(2017MS(LH)0523, 2018LH05017);中国铁路总公司科技研究开发计划课题(2017G002-R)

Law of Deformation of Railway Subgrade Caused by Cyclic Freezingand Thawing in Seasonal Frozen Soil Region

YU Jing-fei, ZHANG Wen-yue, LI Ming-hao   

  1. School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou 014000, China
  • Received:2019-01-18 Online:2020-05-01 Published:2020-06-10

摘要: 为探究冻融循环作用对季节性冻土区铁路路基变形特性的影响,以兰新铁路的路基填土为研究对象进行冻融循环试验和固结压缩试验,得到了冻融变形和压缩特性的变化规律,并利用正交试验对压缩特性的影响因素进行显著性分析。试验结果表明:随着冻融循环次数的增加,冻胀率和融沉系数均呈多项式函数增加;在相同冻融循环次数下,两者均与含水率呈正相关,与压实度呈负相关。压缩模量随冻融循环次数的增加先增加,最终趋于稳定,各因素及其交互作用对压缩模量的影响从高到低依次为压实度B、含水率C、冻融循环次数A、B和C的交互作用BC、A和B的交互作用AB、A和C的交互作用AC。建议选取9次冻融循环后的压缩模量作为兰新铁路路基强度设计值,该研究成果对防治冻胀融沉和控制路基变形具有一定的指导意义。

关键词: 季节性冻土, 铁路路基, 冻融循环, 冻胀率, 融沉系数, 压缩模量, 显著性分析

Abstract: In order to explore the influence of cyclic freezing and thawing on the deformation characteristics of railway subgrade in seasonal frozen soil region, we performed freeze-thaw cycle test and consolidation compression test on the roadbed filling of Lanzhou-Xinjiang Railway as the research object. Through the tests we obtained the regularities of railway subgrade deformation caused by freeze-thaw cycles and compression characteristics. Moreover, we analyzed the influencing factors of compression characteristics by significance test via orthogonal analysis. Results revealed that the frost heave rate and the melting subsidence coefficient both increased in a power function with the increase of the number of freeze-thaw cycles, and both were positively correlated with water content and negatively correlated with compaction degree at the same freeze-thaw cycle. The compressive modulus of subgrade soil increased at first and then stabilized with the proceedings of cyclic freezing and thawing. The compaction degree (B) had the largest influence on compressive modulus, followed by water content (C), freeze-thaw cycle (A), the interaction between B and C, the interaction between A and B, and the interaction between A and C in sequence. We recommend choosing the compression modulus after nine freeze-thaw cycles as the design value of the road strength of Lanzhou-Xinjiang Railway. The research finding is of guiding significance for the prevention and control of frost heaving and subsidence of railway subgrade.

Key words: seasonal frozen soil, railway subgrade, freeze-thaw cycle, frost heave rate, melting subsidence coefficient, compression modulus, significance analysis

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