土中结合水含量对红黏土热导率的影响  

Effect of Bound Water Content in Red Clay on Its Thermal Conductivity

作　　者：杨成琳 曾召田[1,2] 曹珊珊 车东泽 唐双慧 Yang Chenglin;Zeng Zhaotian;Cao Shanshan;Che Dongze;Tang Shuanghui(College of Civil Engineering,Guilin University of Technology,Guilin,Guangxi 541004,P.R.China;Guangxi Key Laboratory of Geomechanics and Engineering,Guilin University of Technology,Guilin,Guangxi 541004,P.R.China)

机构地区：[1]桂林理工大学土木工程学院,广西桂林541004 [2]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004

出　　处：《地下空间与工程学报》2025年第1期118-122,149,共6页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(42167020);广西自然科学基金(2023GXNSFAA026187)。

摘　　要：以广西地区2种红黏土为研究对象,通过等温吸附试验确定了其结合水类型和含量;同时,基于压汞试验从微观角度解释2种红黏土吸附结合水量不同的本质原因;在此基础上,利用热探针法测出2种红黏土试样在不同含水率条件下的热导率,探讨土中结合水含量对红黏土热导率的影响规律。结果表明:桂林红黏土和柳州红黏土中的吸附结合水总量分别为22.417%和10.957%,前者约为后者的2倍,其本质原因主要在于2种红黏土中矿物成分的差异;桂林红黏土比柳州红黏土具有更多的小孔隙含量,其孔隙率高,比表面积大,吸附结合水的能力强;2种红黏土的热导率随结合水含量的递增而增加,热导率与结合水含量具有显著的线性正相关关系;结合水含量对热导率的影响可以归结于土中结合水膜和“液桥”作用两个方面。Taking the 2 types red clay in Guangxi area as the research object,through the isothermal adsorption test,the type and content of the adsorbed bound water in the red clay were determined,and the nature of the difference in the amount of adsorbed bound water in the two red clays was explained from the microscopic perspective by the mercury-pressure test.Based on this,the thermal conductivity of two kinds of red clay samples under different water contents was measured by the thermal probe method,and the influence of bound water content on the thermal conductivity of red day was discussed.The results showed that the total amount of adsorbed bound water in Guilin red clay and Liuzhou red clay was 22.417%and 10.957%,respectively,and the former one was about twice as much as the latter one,mainly due to the difference in mineral composition of the two red clays.The red clay in Guilin has a higher content of small pores compared to that in Liuzhou,resulting in a higher porosity and greater specific surface area,which endows it with a stronger capacity to adsorb and bind water.The thermal conductivity of the two red clays increased with the increase of the bound water content.The effect of bound water content on thermal conductivity can be attributed to both the bound water film and the"liquid bridge"effect in the soil.

关 键 词：红黏土 结合水 热导率 压汞试验 比表面积 

分 类 号：TU443[建筑科学—岩土工程]