院报 ›› 2021, Vol. 38 ›› Issue (11): 115-120.DOI: 10.11988/ckyyb.20200707

• 岩土工程 • 上一篇    下一篇

(NH4)2CO3作用下饱和红黏土的崩解效应

李善梅1,2, 刘之葵1,2, 蒙剑坪1,2   

  1. 1.桂林理工大学 土木与建筑工程学院,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
  • 收稿日期:2020-07-17 修回日期:2020-09-26 出版日期:2021-11-01 发布日期:2021-11-08
  • 作者简介:李善梅(1983-),女,广西桂林人,讲师,博士,主要从事岩土工程方向的教学与研究工作。E-mail:lishanmei@glut.edu.cn
  • 基金资助:
    国家自然科学基金项目(41867039);广西自然科学基金项目(2017GXNSFAA198238);广西中青年教师基础能力提升项目(2019KY0277,2020KY06028);桂林理工大学博士科研启动基金项目(RD19100185);广西岩土力学与工程重点实验室主任基金项目(桂科能19-Y-21-3);广西建筑新能源与节能重点实验室主任基金项目(桂科能19-J-21-11)

Disintegration Effect of Saturated Red Clay under the Action of (NH4)2CO3

LI Shan-mei1,2, LIU Zhi-kui1,2, MENG Jian-ping1,2   

  1. 1. College of Civil Engineering and Architecture, Guilin University of Technology, Guilin 541004, China;
    2. Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology, Guilin 541004, China
  • Received:2020-07-17 Revised:2020-09-26 Online:2021-11-01 Published:2021-11-08

摘要: 为研究(NH4)2CO3溶液对红黏土崩解性的影响,以桂林红黏土为研究对象,通过自制的崩解装置,测试不同浓度(NH4)2CO3溶液作用下饱和红黏土的崩解特性。比较红黏土与(NH4)2CO3作用前后溶液的pH值、土体C和N元素含量及微形貌,分析崩解的微观机理。同时,结合溶液作用下抗剪强度和渗透性探讨崩解行为。试验发现,饱和红黏土的崩解性随溶液浓度增大而增大;其崩解过程可划分为快速崩解、稳定崩解和完成3个阶段,第Ⅰ阶段持续时间较短,主要是土样从环刀脱出过程中扰动所致;第Ⅱ阶段持续时间长,为崩解的主要阶段,与结合水膜厚度、粒间作用力、胶结作用、强度和渗透性等诸多因素密切相关。

关键词: 饱和红黏土, 崩解, (NH4)2CO3溶液, 抗剪强度, 渗透系数, 微观形貌

Abstract: The disintegration characteristics of saturated red clay from Guilin were examined under the action of (NH4)2CO3 solution of different concentrations through a self-made disintegration device. The microscopic mechanism of disintegration was analyzed from aspects including the pH value of solution, the content of elements C and N in the soil, as well as the micromorphology of soil before and after the action of (NH4)2CO3. Meanwhile, the macroscopic effect of disintegration was discussed in terms of shear strength and permeability. Test results manifested that the disintegration of saturated red clay intensified with the increase of solution concentration, and the disintegration process was divided into rapid, constant and stable stages. The first stage, which lasted a short time, was mainly caused by disturbance of the ring cutter; and the second stage, as the main stage of disintegration and lasting long, was closely related with the thickness of water film, the intergranular forces, the cementation force, the strength and the permeability of soil.

Key words: saturated red clay, disintegration, (NH4)2CO3 solution, shear strength, permeability coefficient, micromorphology

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