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冰川冻土 ›› 2020, Vol. 42 ›› Issue (2): 457-466.doi: 10.7522/j.issn.1000-0240.2020.0047

• 寒区工程与灾害 • 上一篇    下一篇

多年冻土区铁路路基导热系数监测与分析

张明礼1,3,4(), 王斌2, 周志雄3, 颉俊杰1, 王得楷5, 岳国栋3, 李广3   

  1. 1.公路建设与养护技术、 材料及装备交通运输行业研发中心(甘肃路桥建设集团有限公司),甘肃 兰州 730030
    2.新疆维吾尔自治区交通规划勘察设计研究院,新疆 乌鲁木齐 830000
    3.兰州理工大学 土木工程学院,甘肃 兰州 730050
    4.中国科学院 西北生态环境资源 研究院 冻土工程国家重点实验室,甘肃 兰州 730000
    5.甘肃省科学院 地质自然灾害防治研究所,甘肃 兰州 730000
  • 收稿日期:2019-07-26 修回日期:2020-07-20 出版日期:2020-08-31 发布日期:2020-09-11
  • 作者简介:张明礼(1987 - ), 男, 陕西安康人, 副教授, 2016年在中国科学院寒区旱区环境与工程研究所获博士学位, 从事寒区岩土工程研究. E-mail:mingli_0919@126.com.
  • 基金资助:
    国家自然科学基金项目(41801033);冻土工程国家重点实验室开放基金项目(SKLFSE201804);兰州理工大学红柳优秀青年人才计划;公路建设与养护技术、 材料及装备交通运输行业研发中心(甘肃路桥建设集团有限公司)开放基金项目(GLKF201809)

Monitoring and analysis of the thermal conductivity of railway subgrade in the permafrost regions

Mingli ZHANG1,3,4(), Bin WANG2, Zhixiong ZHOU3, XIE Junjie1, Dekai WANG5, Guodong YUE3, Guang LI3   

  1. 1.Research and Development Center of Transport Industry of Technologies,Materials and Equipments of Highway Construction and Maintenance (Gansu Road & Bridge Construction Group),Lanzhou 730030,China
    2.Xinjiang Transportation Planning Surveying and Design Institute,Urumqi 830000,China
    3.College of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China
    4.State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environmental and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
    5.Geological Hazards Prevention Institute,Gansu Academy of Sciences,Lanzhou 730000,China
  • Received:2019-07-26 Revised:2020-07-20 Online:2020-08-31 Published:2020-09-11

摘要:

为分析冻融过程、 道砟覆盖及降雨对多年冻土区铁路路基土体导热系数的影响, 对青藏高原多年冻土区铁路路基试验段和天然地表土体开展导热系数、 温度、 水分原位监测。结果表明: 融化期导热系数波动均明显大于冻结期, 天然场地导热系数在冻结期大于融化期, 而无道砟覆盖路基土体和道砟覆盖路基土体的导热系数在冻结期小于融化期, 与通常的认知和温度场模拟取值相反; 道砟层的保温和阻水效应导致道砟覆盖路基土体含水量和导热系数均小于无道砟覆盖路基土体, 冻结期路基土体导热系数有减小趋势, 道砟覆盖路基土体尤为显著; 降雨入渗增大土体导热系数, 低含水量的道砟覆盖路基土体导热系数对降雨的响应最强烈。寒区路基工程数值模拟时, 应考虑水热变化对导热系数的影响, 不宜采用固定相变区间的分段函数或阶跃函数预估导热系数。

关键词: 铁路路基, 多年冻土, 导热系数, 现场监测, 降雨入渗

Abstract:

In order to analyze the effects of freezing and thawing process, ballast cover and rainfall on thermal conductivity, the in-situ monitoring of thermal conductivity, temperature and moisture of subgrade and natural soil in the test section of permafrost railway roadbed was carried out in the Qinghai-Tibet Plateau. The results show that the fluctuation of thermal conductivity during the melting period is more obvious than the freezing period. The thermal conductivity during the thawing period is larger than the freezing period in natural site, but the thermal conductivities of gravel soil subgrade and ballast covered subgrade during the freezing period are smaller than the thawing period. The monitoring results of subgrade soil are contrary to the general cognition and simulation value of temperature field. Moisture content and thermal conductivity of gravel soil subgrade are higher than ballasted subgrade soil due to the thermal insulation and water blocking effects of ballast layer. Meanwhile, the thermal conductivity of subgrade soil during freezing period tends to decrease, especially for the ballast subgrade soil. The rainfall infiltration increases the thermal conductivity of the soil. And the thermal conductivity of the low water content ballast subgrade has a considerable response to rainfall. In the numerical simulation of railway subgrade engineering in cold area, the influence of hydrothermal change on thermal conductivity should be considered. It is not appropriate to use the piecewise function or step function of the fixed phase change interval to estimate the thermal conductivity.

Key words: railway subgrade, permafrost, thermal conductivity, field monitoring, rainfall infiltration

中图分类号: 

  • U213.14