含水裂隙冻融过程中冻胀力演化及影响因素研究  

Study on the evolution and influencing factors of frost heaving force of waterbearing cracks during freezing-thawing process

作　　者：贾海梁[1] 赵思琪 丁顺 王婷 董元宏 谭贤君[5] JIA Hailiang;ZHAO Siqi;DING Shun;WANG Ting;DONG Yuanhong;TAN Xianjun(College of Architecture and Civil Engineering,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China;School of Civil Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China;College of Geology and Environment,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China;College of Civil Engineering,Xijing University,Xi'an,Shanxi 710199,China;State Key Laboratory of Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)

机构地区：[1]西安科技大学建筑与土木工程学院,陕西西安710054 [2]大连理工大学土木工程学院,辽宁大连116024 [3]西安科技大学地质与环境学院,陕西西安710054 [4]西京学院土木工程学院,陕西西安710199 [5]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《岩石力学与工程学报》2022年第9期1832-1845,共14页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(41702334,42071083)。

摘　　要：岩体冻融损伤的本质是水-冰相变过程中冻胀力驱动的既有裂隙的扩展,因而,研究裂隙中冻胀力的产生和演化过程是岩体冻融损伤研究中的核心问题,也是揭示岩体冻融损伤机制的基本前提。以含单裂隙灰岩为研究对象,监测冻融过程中裂隙内部温度变化、裂隙冰的形成过程以及裂隙内部冻胀力演化和裂隙端部冻胀变形,并分析不同变量(冻结速率、裂隙含水量(水占裂隙体积的比例)、裂隙深度)对裂隙冻胀特性的影响。试验结果表明:(1)冻融过程中裂隙内部温度变化可分6个阶段,在快速冻结阶段有明显的过冷和热弛豫现象,裂隙水由外向内冻结,形成冰壳将未冻水束缚在内;(2)裂隙内部冻胀力和冻胀变形的演化过程可分为5个阶段,阶段2为冻胀力和冻胀变形的产生与演化阶段,在此阶段冻胀力快速增长升至峰值后又迅速下降,冻胀变形演化则可分2种模式:快速增大后迅速降低和快速增大后缓慢增大;(3)不同变量条件下对裂隙水冻结过程中过冷度、热弛豫持续时间、最大冻胀力值影响最为显著,当裂隙深度较大时裂隙端部将会出现开裂现象。根据上述实验结果分析认为:冻融过程中冻胀力的产生和演化受裂隙中未冻水密封条件控制;密封条件的形成伴随着“未冻水冻结→冰壳断裂→未冻水挤出→冰壳闭合”过程的反复进行;密封条件形成后裂隙是否出现冻胀扩展取决于冻结速率、初始含水量及裂隙深度。The freezing-thawing damage nature of rock mass is the expansion of existing cracks driven by the frost heaving force in the process of water-ice transformation. Therefore,the study of the generation and evolution of the frost heaving force in cracks is the core problem in the study of rock mass freezing-thawing damage and the basic premise for revealing the freezing-thawing damage mechanism of rock mass. In this paper,the crack internal temperature,the formation process of crack ice,the evolution of the freezing-heaving force inside the crack and the freezing-heaving deformation at the crack end are monitored in the limestone with single crack during freezingthawing,and effects of different variables(freezing rate,crack water content(water ratio of the crack volume),crack depth) on frost heave characteristics of cracks. The results show that the temperature change in the crack can be divided into six stages during freezing-thawing. In the rapid freezing stage,there are obvious phenomena of undercooling and thermal relaxation,and the crack water freezes from the outside to the inside,forming an ice shell to restrict the unfrozen water. Fracture internal frost heaving force and frost heave deformation evolution process can be divided into five stages. In the stage 2,the frost heave force grows to peak and then rapid decline,while the frost heave deformation evolution can be divided into two modes:rapid increase first and then rapid decrease,and rapid increase first and then slow increase. The influence of different variables on the degree of undercooling,the duration of thermal relaxation and the maximum frost heaving force in the water freezing process is significant. When the crack depth is large,the crack will appear at the crack end. Based on the above experimental results,it can be concluded that the generation and evolution of the frost heaving force in the freezing-thawing process are controlled by the unfrozen water seal condition in the crack,that the formation of the sealing condition is accompanied by a

关 键 词：岩石力学 裂隙岩体 冰楔作用 冻胀力 冻胀扩展 密封条件 

分 类 号：TU45[建筑科学—岩土工程]