改良红黏土的强度和崩解特性及其微观机理  

Strength and Disintegration Characteristics of Improved Red Clay and Its Micro⁃mechanism

作　　者：张炳晖[1,2] 段睿 谢艳华 韩伟超[1] 刘帅宇 ZHANG Binghui;DUAN Rui;XIE Yanhua;HAN Weichao;LIU Shuaiyu(School of Civil Engineering,Guilin University of Technology,Guilin Guangxi 541004,China;School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510610,China;Guilin Institute of Aerospace Industry,Guilin Guangxi 541004,China)

机构地区：[1]桂林理工大学土木工程学院,广西桂林541004 [2]华南理工大学土木与交通学院,广州510610 [3]桂林航天工业学院,广西桂林541004

出　　处：《铁道建筑》2024年第8期123-129,共7页Railway Engineering

基　　金：国家自然科学基金(11962004);广西高校中青年教师科研基础能力提升项目(2022KY0786)。

摘　　要：为探究土体强度特性与崩解特性之间的关系,通过提高土体压实度和具有较好生态效益的高分子生物聚合物瓜尔胶(Guar Gum)掺量两种方法对红黏土进行改良。开展不同压实度与瓜尔胶掺量改良红黏土的直剪试验、崩解试验及扫描电镜试验,研究分析了压实度以及瓜尔胶掺量对红黏土崩解特性及其抗剪强度的影响,并揭示了其微观机理。结果表明:增大压实度与掺入瓜尔胶可以有效提高红黏土的力学性质以及抗崩解性。随着压实度增大,试样黏聚力呈线性增长,内摩擦角有小幅度升高;掺入瓜尔胶对土体的内摩擦角与黏聚力均有较大提升。经过瓜尔胶改良后的红黏土最终崩解率明显降低,当掺量为0.25%时,试样不再发生崩解;增大压实度与掺入瓜尔胶两种方法都能提高土体黏聚力,增大内摩擦角,使土体粒间吸引力变强,从而提升土体的强度与抗崩解性能;与提高土体压实度相比,红黏土中掺入瓜尔胶对提升红黏土的水稳性有更好的效果。To explore the relationship between soil strength characteristics and disintegration characteristics,two methods were used to improve red clay:increasing soil compaction and increasing the content of high molecular weight biopolymer guar gum,which has good ecological benefits.By conducting direct shear tests,disintegration tests,and scanning electron microscopy experiments on red clay with different compaction degrees and guar gum contents,the effects of compaction degrees and guar gum contents on the disintegration characteristics and shear strength of red clay were studied and analyzed,and their microscopic mechanisms were revealed.The results show that increasing the compaction degree and adding guar gum can effectively improve the mechanical properties and anti-disintegration of red clay.With the increase of compaction degree,the cohesion of the sample increases linearly,and the internal friction angle increased slightly.The addition of guar gum could significantly improve the internal friction angle and cohesion of soil.The final disintegration rate of red clay improved by guar gum is significantly reduced,and the disintegration of the sample no longer occurred when the dosage was 0.25%.Both methods of increasing soil compaction and adding guar gum can improve soil cohesion,increase internal friction angle,and enhance the attraction between soil particles,thereby improving soil strength and resistance to disintegration.Compared with improving soil compaction,adding guar gum to red clay has a better effect on enhancing its water stability.

关 键 词：铁路路基 土体改良 试验研究 红黏土 强度试验 崩解试验 微观机理 

分 类 号：U213.1[交通运输工程—道路与铁道工程]