摘要
黄土高原是中国滑坡事故频发的重灾区,而生态改良材料为黄土边坡生态防护及提高坡面稳定性工程实践提供新方法和新思路。采用植物基生物水泥(Bio-cement,BC)对黄土进行改良处理,通过冻融循环试验对比分析改良前后黄土力学特性的变化,并结合微观结构表征,深入探究BC对黄土改良的作用机制。结果表明:采用BC对黄土进行改良处理后,得到了未改良的试样无侧限抗压强度为154.8kPa,BC-纤维改良后试样的峰值应力最高可达561.1kPa;不同纤维掺量、相同冻融循环次数条件下,峰值强度提高280.61%(15次冻融循环);随冻融次数增加,试样峰值强度显著降低,经15次冻融后,降幅介于18.05%~42.28%;整体而言,BC-低纤维掺量减缓强度损失率,抗渗透性变化规律与之呼应;微观层面,纤维增强颗粒间黏结并提供碳酸钙成核位点,进而形成纤维-碳酸钙晶体-土颗粒集合体;研究成果有助于深入探究生态改良材料对黄土改良的适用性,为其应用和推广提供试验依据。
The Loess Plateau is a disaster-prone area with frequent landslides in China.This study aims to explore the feasibility of using ecological improvement materials for loess,and to provide new methods and ideas for the engineering practice of ecological protection of loess slopes and enhancement of slope stability.The plant-based bio-cement(BC)was used to improve the loess.The changes of mechanical properties of loess before and after improvement were compared and analyzed by freeze-thaw cycle test.Combined with microstructure characterization,the mechanism of BC on loess improvement was deeply explored.The results show that:After the loess is modified by BC,the unconfined compressive strength of the unmodified sample is 154.8 kPa,and the peak stress of the BC-fiber modified sample is up to 561.1 kPa.Under the condition of different fiber content and the same number of freeze-thaw cycles,the peak strength increases by 280.61%(15 freeze-thaw cycles)with the increase of freeze-thaw cycles,the peak strength of the sample decreases significantly.After 15 freeze-thaw cycles,the decrease is between 18.05%and 42.28%;On the whole,BC-low fiber content slows down the strength loss rate,and the change law of permeability resistance corresponds to it;At the micro level,fibers enhance the bonding between particles and provide calcium carbonate nucleation sites,thus forming fiber-calcium carbonate crystal-soil particle aggregates;The research results are helpful to further explore the applicability of ecological improvement materials to loess improvement,and provide experimental basis for its application and promotion.
作者
康江
张斌
刘晓军
代俊宁
严浩
王帅
KANG Jiang;ZHANG Bin;LIU Xiaojun;DAI Junning;YAN Hao;WANG Shuai(Shaanxi Engineering Investigation and Research Institute Co.,Ltd.,Xi'an 710068,China;Shaanxi Institute of Geology and Mineral Resources Innovation Co.,Ltd.,Xi'an 710054,China)
出处
《西安科技大学学报》
北大核心
2025年第6期1211-1221,共11页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金项目(4237021046)。
关键词
生物水泥
黄土
改良
冻融循环
物理力学特性
微观特征
bio-cement
loess
improvement
freeze-thaw cycle
physical and mechanical properties
micro characteristic
