摘要
针对黄土区土体松散、颗粒胶结弱的特点,通过力学试验与室内盆栽试验,研究了酪蛋白(Cas)和海藻酸钠(SA)在不同掺量、养护龄期及含水率条件下对黄土力学性能及黑麦草生长的影响,并结合扫描电镜(SEM)分析其微观机制。结果表明:Cas与SA均能有效提升黄土的力学性能,且随养护龄期延长、含水率降低,土体强度逐渐增强;Cas改良土的无侧限抗压强度(UCS)随掺量增加呈线性增长,5%掺量时在14%含水率、养护14 d条件下达到峰值352.85 kPa,相比素土(223.44 kPa)增幅达57.92%;SA改良土的UCS随掺量呈抛物线变化,2%掺量时达峰值353.57 kPa;Cas黏聚力随掺量显著提升,而SA在低含水率下黏聚力表现更优;Cas掺量增加使黑麦草发芽率稳步提高(5%掺量时达96%),茎高与根深稳定增长;SA在2%掺量时对发芽、茎高和根深的促进效果最佳;Cas通过填充孔隙和胶结作用增强土体结构,SA则通过离子交联形成“蛋盒”结构的三维凝胶网络,提升整体稳定性。两种改良剂的最优掺量均与力学性能和植物生长的协同提升相对应,研究成果可为黄土区边坡改良工程的设计与实践提供科学支撑和参数参考。
In light of the observed characteristics of loose soil and low particle bonding strength in loess regions,a series of mechanical tests and indoor pot experiments were conducted.We investigated how different concentrations of casein(Cas)and sodium alginate(SA),curing periods,and moisture contents affected the mechanical properties of loess and the growth of ryegrass.Scanning electron microscopy(SEM)was used to analyze the microscopic characteristics of the soil samples prior to and following solidification.The results show that both Cas and SA can enhance the mechanical properties of loess,and the soil strength increases gradually with the increase of curing period,but the decrease of moisture content.As the proportion of Cas increases,the unconfined compressive strength(UCS)of Cas-modified loess exhibits a linear growth trend,which reaches a peak value of 352.85 kPa under Cas concentration of 5%,moisture content of 14%,and curing period of 14 days.Compared with unmodified soil,the UCS of Cas-modified loess increased by 57.92%.The UCS of SA-modified soil exhibits a parabolic trend with varying SA concentrations,reaching a peak of 353.57 kPa at 2%SA dosage.The cohesion of the Cas-modified soil increases with Cas content;whereas the SA-modified soil demonstrates more pronounced cohesion at low moisture content.The promotional effect of the two amendments with optimal concentrations on ryegrass growth are consistent with the enhancement of soil mechanical properties.Specifically,as the increase of Cas dosage,the germination rate steadily increases(reaching 96%at 2%Cas dosage),so do the stem height and root depth.At a 2%SA dosage,the promotional effects on ryegrass germination,stem height,and root depth reach their peak.According to the scanning electron microscopy(SEM)imagery,Cas strengths the soil structure by filling up the space between pores and cementation action,while the molecular chains of SA can form an“egg carton”-shaped three-dimensional gel network to enhance the overall stability.The findings of this study can serve as a reference for the design and implementation of slope improvement projects in loess regions.
作者
张晨
茹含
陈昊
刘佳骏
杨秀娟
ZHANG Chen;RU Han;CHEN Hao;LIU Jiajun;YANG Xiujuan(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China)
出处
《水资源与水工程学报》
北大核心
2025年第5期178-186,共9页
Journal of Water Resources and Water Engineering
基金
内蒙古自治区科技厅重大专项(150000243033210000057)。
关键词
黄土
改良
酪蛋白
海藻酸钠
力学强度
生长指标
微观结构
loess
remediation
casein
sodium alginate
mechanical strength
growth indicator
microstructure
