酶诱导碳酸钙沉淀处理对紫色土坡面片蚀过程及泥沙分选的影响  

Influences of enzyme-induced carbonate precipitation on the sheet erosion and sediment sorting of purple soil slopes

作　　者：向瑞 郭俊奎 张伦 夏振尧[1,2,3] 刘德玉[1,2] 丁瑜 肖海[1,2,3] XIANG Rui;GUO Junkui;ZHANG Lun;XIA Zhenyao;LIU Deyu;DING Yu;XIAO Hai(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area,Ministry of Education,Yichang 443002,China;College of Civil Engineering&Architecture,China Three Gorges University,Yichang 443002,China;Engineering Research Center of Eco-environment in Three Gorges Reservoir Region,Ministry of Education,Yichang 443002,China)

机构地区：[1]三峡库区地质灾害教育部重点实验室,宜昌443002 [2]三峡大学土木与建筑学院,宜昌443002 [3]三峡库区生态环境教育部工程研究中心,宜昌443002

出　　处：《农业工程学报》2024年第24期81-88,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(U21A2031,42277323,52378351);土木工程防灾减灾湖北省引智创新示范基地项目(2021EJD026)。

摘　　要：为探究酶诱导碳酸钙沉淀(enzyme induced carbonate precipitation,EICP)处理对坡面片蚀过程及泥沙分选的影响,该研究以三峡库区紫色土坡面为研究对象,设置6种喷洒处理(裸坡对照CK,单施脲酶和4种胶结液浓度的EICP:0.5、1.0、1.5和2.0 mol/L),开展降雨强度为60和120 mm/h的人工模拟降雨试验,分析坡面片蚀(产流产沙)过程和次降雨侵蚀泥沙分选情况,并通过扫描电镜揭示EICP影响坡面片蚀的微观机制。结果表明:与CK相比,单施脲酶具有一定的增流减沙效果,EICP处理具有显著的增流减沙效果(P<0.05),增流减沙效果随着胶结液浓度的增加呈现先增加后减小的变化规律,在浓度为1.5 mol/L时增流减沙效果最佳。不同胶结液浓度处理间的产流总量和产沙总量无显著性差异(P>0.05),说明低浓度(0.5 mol/L)时已能够较好地发挥控制片蚀效果。侵蚀泥沙呈现黏粒、细粉粒和粗粉粒富集而砂粒亏损的分选现象,EICP处理后坡面侵蚀泥沙分选程度有所降低。微观分析表明EICP处理在土颗粒的间隙和表面均出现球形碳酸钙沉淀和脲酶丝状物质,从而提高表层土体的整体性,进而提高土体抗侵蚀性能。该研究结果将有助于揭示EICP减蚀机理,并为三峡库区水土保持提供理论依据。Enzyme induced carbonate precipitation(EICP)is one of the innovative geotechnical techniques to reinforce the soil.Specifically,urease can be directly utilized to catalyze the hydrolysis of urea,and then form the calcium carbonate crystals.EICP has promising potential to control rainfall-induced erosion.However,previous research has focused primarily on the overall effect of erosion reduction.It is still lacking in the influence of EICP on erosion processes under different erosion patterns.Among them,different erosion patterns are characterized by distinct processes and mechanisms,where sheet erosion is the initial phase of slope erosion to serve as the most important evolution of soil erosion.It is one of the most complex processes of slope water erosion,indicating significant sediment sorting.Therefore,this study aims to explore the influence of EICP spray treatment on sheet erosion and sediment sorting.The purple soil slope in the Three Gorges Reservoir Area(TGRA)was taken as the research object.Six spraying treatments(bare slope as control check(CK),only urease spray treatment,and EICP spray treatment with 4 cementing solution concentrations(0.5,1.0,1.5,and 2.0 mol/L))were set.Simulated rainfall experiments with two rainfall intensities(60 and 120 mm/h)were carried out to analyze the sheet erosion(including runoff and erosion)and the sediment sorting of sub-rainfall events.Moreover,the microscopic influence mechanism of EICP on sheet erosion was revealed using scanning electron microscopy.The results indicated that the total runoff for only urease spray treatment increased on average by 10.68%,whereas,the total erosion was reduced on average by 43.74%,respectively,compared with the CK;The total runoff under EICP spray treatments increased on average by 29.51%to 50.76%,whereas,there was the decrease on average by 85.57%to 90.90%,respectively.The only urease spray treatment showed a certain effect on increasing runoff and reducing sediment.While the EICP spray treatment showed a significant effect on increasing

关 键 词：酶诱导碳酸钙沉淀(EICP) 片蚀 泥沙分选 微观结构 水土保持 

分 类 号：S157.1[农业科学—土壤学]