摘要
针对浅表层黏性土与大气环境相互作用强烈,在气候因素影响下工程性质恶化而诱发地质灾害和生态环境的问题,采用生物胶和稻秸秆纤维复合改良黏性土的强度特性,通过无侧限抗压强度试验和直剪试验探究了单掺和复合改良方式下土体无侧限抗压强度特性及抗剪强度指标的变化规律,分析了生物胶含量和纤维含量对复合改良效果的影响,并基于扫描电镜分析了生物胶-秸秆纤维复合改良黏性土的作用机理。研究结果表明:随着生物胶含量和纤维含量的增加,改良土应力-应变曲线趋于应变硬化,峰值位置后移,且峰后应力衰减减缓;改良土的无侧限抗压强度和抗剪强度显著增强,其主要通过提升黏聚力来增强土体性能,而对内摩擦角影响较小;生物胶通过表面包覆、颗粒联结和孔隙填充改善土体结构,提高纤维-土界面的加筋效果,结合纤维形成的网络框架提升土体的力学性能。
Shallow cohesive soil interacts strongly with the atmospheric environment,and its engineering properties deteriorate severely due to the influence of climate factors,leading to geological disasters and ecological environmental problems.In response to the above issues,a combination of bio-glue and rice straw fiber was introduced to improve the mechanical properties of cohesive soil.Through unconfined compressive strength tests and direct shear tests,the changes in the unconfined compressive strength characteristics and shear strength parameters of soil with single admixture and composites were investigated.The effects of bio-glue and fiber contents on the improvement effect of composite treatment were studied,and the effect mechanism of bio-glue and straw fiber composite modified cohesive soil was analyzed based on scanning electron microscope(SEM).The results show that due to the increase in bio-glue content and fiber content,the stress-strain curves of modified soil tend to behave as strain hardening,with a prolonged peak position and reduced post-peak stress decay.Both unconfined compressive strength and shear strength of modified soil are significantly enhanced,which mainly enhances the soil’s mechanical properties by increasing cohesion and has little effect on the internal friction angle.Bioglue improves soil structure through surface coating,particle bonding,and pore filling,which also improves the reinforcement effect of fiber-soil interface and enhances soil’s mechanical properties by combining the network framework formed by fibers.
作者
梁玉红
刘玲
蒋鹏
刘瑾
车文越
陈志昊
LIANG Yuhong;LIU Ling;JIANG Peng;LIU Jin;CHE Wenyue;CHEN Zhihao(Marine Geological Survey of Jiangsu Province,Nanjing 210007,China;School of Earth Sciences and Engineering,Hohai University,Nanjing 211100,China)
出处
《河海大学学报(自然科学版)》
北大核心
2025年第6期147-157,共11页
Journal of Hohai University(Natural Sciences)
基金
江苏省地质勘查项目(2024)。
关键词
生物胶
秸秆纤维
黏性土
复合改良
强度特性
扫描电镜
bio-glue
straw fiber
cohesive soil
composite modification
strength characteristic
scanning electron microscope
