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。
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.
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
Key words
saturated red clay /
disintegration /
(NH4)2CO3 solution /
shear strength /
permeability coefficient /
micromorphology
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 彭旭东,戴全厚,李昌兰.中国西南喀斯特坡地水土流失/漏失过程与机理研究进展[J].水土保持学报,2017,31(5):1-8.
[2] 王恒松,熊康宁,张芳美.地形因子对喀斯特坡面水土流失影响的机理研究[J].水土保持通报,2015,35(4):1-7.
[3] SHI Hui, SHAO Ming-an. Soil and Water Loss from the Loess Plateau in China [J]. Journal of Arid Environments, 2000,45(1):9-20.
[4] 颜 波,汤连生,胡 辉,等.花岗岩风化土崩岗破坏机理分析[J].水文地质工程地质,2009(6):68-71,84.
[5] 张晓媛,范昊明,杨晓珍,等.容重与含水率对砂质黏壤土静水崩解速率影响研究[J].土壤学报, 2013, 50(1): 214-218.
[6] 徐 岗,裴向军,袁进科,等. 改性纳米硅材料加固松散砂土的工程特性研究[J].水文地质工程地质,2019, 46(4): 142-149.
[7] 杨晴雯,裴向军,黄润秋. 改性钠羧甲基纤维素加固粉砂土水稳性及稳定机理分析[J].raybet体育在线
学报,2019,36(12):107-112.
[8] 刘伟超,杨广庆,熊保林,等. 低液限粉土水理特性试验研究[J].地下空间与工程学报,2015(4):926-932.
[9] 常方强.福建省平潭岛东北部软质海崖蚀退特征研究[J].海洋科学,2016,40(4):100-107.
[10]王菁莪,项 伟,毕仁能. 基质吸力对非饱和重塑黄土崩解性影响试验研究[J].岩土力学,2011,32(11):3258-3262.
[11]GARAKANI A, HAERI M, KHOSRAVI A, et al. Hydro-mechanical Behavior of Undisturbed Collapsible Loessial Soils under Different Stress State Conditions[J]. Engineering Geology, 2015,195:28-41.
[12]谷天峰,袁 亮,胡 炜,等.黑方台黄土崩解性试验研究[J].水文地质工程地质,2017,44(4):62-70.
[13]THYAGARAJ T, DAS A P. Physico-chemical Effects on Collapse Behavior of Compacted Red Soil[J]. Géotechnique, 2017, 67(7): 559-571.
[14]DAS A P, THYAGARAJ T. Collapse Behavior of Compacted Red Soil[J]. International Journal of Geotechnical Engineering, 2018, 12(1), doi: 10.1080/19386362.2016.1243506.
[15]RAO S M,REVANASIDDAPPA K. Collapse Behavior of a Residual Soil[J]. Géotechnique,2002,52(4):259-268.
[16]蒋小珍,雷明堂,管振德.单层土体结构岩溶土洞的形成机理[J].中国岩溶,2012,31(4):426-432.
[17]穆红文,费良军,雷雁斌.膜孔灌肥液自由入渗硝态氮运移特性试验研究[J].干旱地区农业研究,2007,25(2):63-66,79.
[18]高鹏程,张一平,张 海,等.水热耦合作用下尿素转化为铵态氮的动力学模型[J].植物营养与肥料学报,2005,11(1):21-26.
[19]胡浩云,程东娟,高 然,等.膜孔灌玉米农田尿素转化和分布特性研究[J].节水灌溉,2011(12):9-12.
[20]喻朝庆.水-氮耦合机制下的中国粮食与环境安全[J].中国科学,2019, 49(12):2018-2036.
[21]水利部,中国科学院,中国工程院.中国水土流失防治与生态安全:水土流失数据卷[M].北京:科学出版社,2010.
[22]朱兆良.农田中氮肥的损失与对策[J].土壤与环境,2000,9(1):1-2.
[23]农资招商网. 农作物怎样施用尿素好 尿素正确使用方法大全[EB/OL]. (2018-04-12)[2020-05-15].http://bk.3456.tv/feiliaobk/29113.
[24]李 强,张 正,孙 会,等.土壤崩解速率的一种修正方法[J].水土保持研究,2015,22(6):344-348.
基金
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)
PDF(1868 KB)
