某高速铁路沿线天然场地季节冻胀特性监测与分析  

Monitoring and Analysis of Seasonal Frost Heave Characteristics of Natural Sites along a High-speed Railway

作　　者：江凯[1] 王茂靖[1] 冯涛[1] 段光武[1] JIANG Kai;WANG Maojing;FENG Tao;DUAN Guangwu(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《高速铁路技术》2024年第4期100-105,共6页High Speed Railway Technology

基　　金：中国国家铁路集团有限公司重大课题(2016G002-A);中国中铁股份有限公司重大专项项目(2016-重大专项-01);中铁二院工程集团有限责任公司科研项目(KYY2015071)。

摘　　要：某高速铁路沿线季节性冻土大面积分布,本文依据地形地貌、土性成分及水文地质条件等特征,选定14处天然场地。通过冻融周期的监测,得到沿线地基土的冻结融化速率、最大季节冻深及地表变形量等重要数据。通过分析积雪场地及裸露场地的冻结融化过程与地表变形情况,结合气温、降水量、地表雪盖等因素,分析了高速铁路沿线季节性冻土的冻融特性。研究结果表明:(1)沿线有雪条件下天然场地最大冻结深度19~90 cm,平均值为45 cm;(2)沿线季节冻土冻结速率0.27~1.20 cm/d,融化速率普遍大于冻结速率,为0.28~1.92 cm/d;(3)积雪对保持土体温度、抑制土体冻结具有良好效果,能有效缩短冻结、融化时间,使最大冻结深度减小18%~24%;(4)冻胀量呈由西向东增大趋势,其变化规律和气候条件吻合。研究成果可为类似季节性冻土地区高速铁路设计及冻害防治提供借鉴。Seasonal frozen soil is widely distributed along a High-speed railway.This paper selects 14 natural sites based on their topographical features,soil composition,and hydrogeological conditions.Through continuous monitoring over complete freeze-thaw cycles,crucial data such as the freezing and thawing rates of the subgrade soil,maximum seasonal frost depth,and surface deformation along the route were obtained.By analyzing the freeze-thaw process and surface deformation in snow-covered and exposed sites,combined with factors like temperature,precipitation,and snow thickness,the freeze-thaw characteristics of seasonal frozen soil along the high-speed railway are summarized.The research findings indicate:(1)The maximum freezing depth of natural sites under the snow condition is 19~90 cm,with an average of 45 cm.(2)The freezing rate varies from 0.27 cm/d to 1.20 cm/d,while the thawing rate,generally higher than the freezing rate,ranges from 0.28 cm/d to 1.92 cm/d.(3)Snow cover effectively maintains soil temperature and inhibits soil freezing,significantly shortening the duration of the freezing and thawing processes,resulting in a reduction of the maximum freezing depth by 18%to 24%.(4)The frost heave exhibits an increasing trend from west to east,and its variation pattern aligns with climatic conditions.These research outcomes provide valuable insights for the design of high-speed railways and the prevention of frost damage in similar seasonal frozen soil regions.

关 键 词：高速铁路 季节冻土 冻胀特性 长期监测 

分 类 号：TU44[建筑科学—岩土工程] U238[建筑科学—土工工程]