水土保持通报2026，Vol.46Issue(2)：14-22,9.DOI:10.13961/j.cnki.stbctb.2026.02.038
红壤中无定形氧化铁-高岭石胶结体系的结构和抗剪强度
Structure and shear strength of amorphous iron oxide-kaolinite cementation system in red soil
摘要
Abstract
[Objective]The key mechanisms by which amorphous iron oxide regulates the mechanical properties of Benggang soil were analyzed from a microscopic perspective in order to provide a theoretical basis for the prevention and control of Benggang erosion.[Methods]Kaolinite,the dominant clay mineral in soil from a typical Benggang area of Fujian Province,was selected as the research object.By incorporating amorphous iron oxide at different concentrations(1,2,3,and 10 g/kg)into kaolinite and utilizing X-ray diffraction(XRD),scanning electron microscopy(SEM),and direct shear tests,this study analyzed its regulatory effects on soil microstructure and shear strength parameters.[Results]XRD analysis revealed that amorphous iron oxide did not undergo a chemical reaction with kaolinite but primarily altered mineral characteristics through physical coating.The concentration of amorphous iron oxide significantly influenced the distribution of cemented aggregates across different particle sizes,demonstrating a pronounced regulatory role in the formation of aggregates within the 2-250 μm range.Among microstructural parameters,only particle long-axis and roundness exhibited significant changes.The long-axis decreased by 22％in samples with the 3 g/kg treatment,while roundness was reduced by 25％in samples with the 2 g/kg treatment.The coefficients of variation for all other parameters remained below 15％.The treatment with 3 g/kg consistently exhibited the highest shear strength across all confining pressure levels.The enhancement in shear strength was closely associated with the observed microstructural alterations.Further analysis indicated that the 3 g/kg treatment resulted in the most substantial improvement in cohesion,which increased by 24.82％compared to pure kaolinite.In contrast,the internal friction angle varied by less than 5.30％.[Conclusion]Amorphous iron oxide enhances soil shear strength by optimizing soil structure through cementation and encapsulation.关键词
崩岗/微观结构/胶结作用/黏聚力/内摩擦角Key words
Benggang/microstructure/cementation/cohesion/internal friction angle分类
农业科技引用本文复制引用
吕义豪,许梦瑶,杨茂进,郑勤敏,林金石,蒋芳市,黄炎和,张越..红壤中无定形氧化铁-高岭石胶结体系的结构和抗剪强度[J].水土保持通报,2026,46(2):14-22,9.基金项目
福建省水利科技项目"崩岗崩壁防塌生态治理技术研发与示范"(KJG21009A （）
MSK202217) （）
水利部重大科技项目(SKS-2022073) （SKS-2022073）
