单向冻结条件下粗颗粒级配土的水热分布及冻胀特性研究  

Experimental study on hydrothermal distribution and frost heave characteristics of coarse-grained graded soil under unidirectional freezing condition

作　　者：刘倩倩[1,2] 蔡国庆 秦宇腾[2] 尹凤杰 李舰 赵成刚[2] LIU Qianqian;CAI Guoqing;QIN Yuteng;YIN Fengjie;LI Jian;ZHAO Chenggang(Key Laboratory of Urban Underground Engineering of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;School of Civil Engineering and Architecture,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学城市地下工程教育部重点实验室,北京100044 [2]北京交通大学土木建筑工程学院,北京100044

出　　处：《岩石力学与工程学报》2023年第9期2329-2340,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(U2034204,52078031,U1834206)。

摘　　要：随着寒旱区高速铁路工程的增多和工程服役时间的增长,气态水迁移引发的路基冻害问题被广泛关注。为深入探究寒区粗颗粒填料的冻胀机制,研制一套考虑水–热–力耦合的土柱试验装置,开展不同补水类型、细颗粒含量、细颗粒类型的单向冻结试验。结果表明:(1)冻结锋面位置受补水方式、细粒土含量的影响较为显著,细粒土类型的影响相对较小。(2)随冻结时间的增长,液–气组合补水和气态水补水均会导致试样含水率不断升高,而前者含水率变化较快。细粒土含量和类型会显著影响气态水迁移量,造成土柱水分分布的明显差异。(3)粗颗粒级配土中液态水很难通过冻胀–抽吸力直接上升至冻结锋面,气态水迁移是造成冻胀发展的重要因素。在高速铁路的长期运营过程中,气态水迁移引发的路基水分积聚和冻胀问题不可忽视。With the increase of high-speed railway construction in cold and arid areas and the increase in engineering service time,the problem of subgrade frost heave caused by vapor migration has been widely concerned.To deeply explore the hydrothermal distribution and frost heave characteristics of coarse-grained graded packing,a soil column test device considering hydro-thermo-mechanical coupling was developed,and unidirectional freezing tests with different water recharge types,fine particle contents,and fine particle types were carried out.The results show that the position of the freezing front is significantly affected by the water recharge method and the content of finegrained soil,while the influence of the type of fine-grained soil is relatively small.With the increase in the freezing time,both liquid-vapor recharge and vapor recharge lead to the increasing water content of the specimen,while the former changes faster.In addition,the fine-grained soil content and type can significantly affect vapor migration,resulting in significant differences in water distribution.It is difficult for liquid water in coarse-grained soil to directly rise to the freezing front through suction,and vapor migration is an important factor in the development of frost heave.In the long-term operation of high-speed railways,the problems of subgrade water accumulation and frost heave caused by vapor migration cannot be ignored.

关 键 词：土力学 粗颗粒级配填料 单向冻结试验 气态水迁移 水热分布 冻胀 

分 类 号：TU43[建筑科学—岩土工程]