冻融循环作用下含水率对粗颗粒填料水分迁移影响的宏细观试验研究  

Macro-micro experimental investigation of the initial water content influence on water migration of coarse-grained soil subjected to freezing and thawing

作　　者：张玉芝[1,2,3] 刘文龙 王海永 张莲海 陈世杰 朱晓东 ZHANG Yuzhi;LIU Wenlong;WANG Haiyong;ZHANG Lianhai;CHEN Shijie;ZHU Xiaodong(Structure Health Monitoring and Control Key Laboratory of Hebei Province,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Collaborative Innovation Center for Performance and Safety of Large-scale Infrastructure,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Key Laboratory of Roads and Railway Engineering Safety Control of Ministry of Education,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Survey and Design Institute Branch,China Railway 19 Bureau Group Co.,LTD,Beijing 102600,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]石家庄铁道大学河北省大型结构健康诊断与控制重点实验室,河北石家庄050043 [2]大型基础设施性能与安全省部共建协同创新中心(石家庄铁道大学),河北石家庄050043 [3]道路与铁道工程安全保障省部共建教育部重点实验室(石家庄铁道大学),河北石家庄050043 [4]石家庄铁道大学土木工程学院,河北石家庄050043 [5]中铁十九局集团有限公司勘察设计院分公司,北京102600 [6]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

出　　处：《冰川冻土》2022年第2期591-601,共11页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金面上项目(52078312);国家自然科学基金青年科学基金项目(51708369,41801277)资助。

摘　　要：冻融循环作用和初始含水率是影响粗颗粒填料水分迁移特征和冻胀融沉变形的两个主要因素。为明确冻融循环作用下,不同初始含水率粗颗粒填料的水分迁移特征及细观机制,采用荧光素为追踪剂,以CT细观机理观测为研究手段,开展了不同初始含水率条件下粗颗粒填料的一系列冻融循环试验,探究了温度场和冻深变化、水分迁移图像、补水量变化、最终含水率分布及CT值变化规律等。试验结果表明,冻深基本随冻融循环的次数增加不断加深,初始含水率越大,不同冻融循环作用下冻深的变化越稳定。外界补水量和液态水迁移高度与初始含水率呈负相关。CT扫描结果分析表明,经历多次冻融循环后,试样中的水分迁移导致土体孔隙结构及颗粒构造发生变化,试样的密度普遍增加,孔隙率以减小为主,进而导致土体发生相应变形。Freezing-thawing and initial water content are the main factors to influence the water migration characteristics,frost heaving and thaw settlement of coarse-grained soil. To clarify the water migration characteristics and micro mechanics of coarse-grained soil with different initial water content under freezing and thawing,fluorescein is taken as the tracer and computerized tomography(CT)is adopted as the micro mechanics method,a series of experiments were carried out to study the temperature field,frost depth development,water supply,final water distribution,water migration images and CT values of the coarse-grained soils with different initial water content under freezing and thawing. Results indicate that the frost depth increase continually with the increasing numbers of the freezing-thawing cycles basically. The external water supply and the migration height of the liquid water are negatively correlated with the initial water content. CT scanning results indicate that after several times of freezing-thawing,the water migration results in the changes of the soil pore and particle structure,then the changes of the samples density increase and the porosity decreases,then the related deformation occurs in the soil.

关 键 词：粗颗粒填料 CT值 冻融循环 初始含水率 水分迁移 

分 类 号：P642.14[天文地球—工程地质学]