摘要
黄土的强水敏性问题是黄土地区生态修复的难点。选取双聚材料,开展崩解试验、变水头渗透试验、土水特征曲线试验以及植物生长生理指标测试等,探讨了双聚材料对重塑黄土工程性能的持水性和生态效应的影响,结合X射线衍射(XRD)、压汞和扫描电子显微镜(SEM)等微观试验,从成分、孔隙分布和颗粒结构等方面综合分析了其加固机理。研究结果表明:双聚材料的掺加能有效提高土样的抗崩解性,耐崩解系数随材料增加而增大。双聚材料能有效增强材料的持水性能,表现为渗透系数减小,土水特征曲线整体上移。双聚材料的掺加能有效提高植物生长和抗旱能力,表现为根冠比更大、根长更长以及超氧化物歧化酶(SOD)值受干旱影响变化量更小。双聚材料的添加并无新物质生成,其作用主要是增强颗粒间联结,生成大量黏聚体,孔隙分布由中孔隙向大孔隙和微小孔隙转化。双聚材料中含有大量极性活性基团酰胺基(—CONH2)吸附架桥使得土颗粒团聚,羟基(—OH)和羧基(—COOH)附着于表面形成保护膜,由团聚粒至团聚体层层包裹促进土壤稳定。
The problem of strong water sensitivity of loess is a difficult point for ecological restoration in the loess regions.In this study,a dual polymer material was selected,and a disintegration test,a variable water head penetration test,a soil water characteristic curve test,and a plant growth physiological index test were conducted.The effect of polymer materials on the water holding capacity and the ecological effects of the engineering properties of reshaped loess,combined with micro-tests such as XRD,mercury intrusion,and SEM,were comprehensively analyzed,and its reinforcement mechanism from the aspects of composition,pore distribution and particle structure was examined.The results show that the addition of polymer mixtures can effectively improve the disintegration resistance of the soil samples,and the disintegration coefficient increases with the increase of the materials.The polymer mixtures can effectively enhance the water retention properties of the material.The coefficientof permeability is reduced and the soil-water characteristic curve is shifted upwards.The addition of polymer mixturess can effectively increase plant growth and drought resistance.The root-shoot ratio is larger,the root length is longer,and the SOD value is more affected by drought.The addition of double-poly material does not produce new substances.Its role is mainly to enhance the interparticle bonding,generate a large number of cohesive bodies,and the pore distribution is transformed from medium pores to large pores and minute pores.The dimerized material is enriched with a large number of polar active group amide groups(—CONH2)to adsorb and bridge the soil particles,and the Hydroxyl(—OH)and carboxyl(—COOH)adhere to the surface to form a protective film.The layers of agglomerates are wrapped to promote soil stabilization.
作者
朱利君
裴向军
张晓超
任童
杨晴雯
ZHU Lijun;PEI Xiangjun;ZHANG Xiaochao;REN Tong;YANG Qingwen(State key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu,Sichuan 610059,China)
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2020年第4期158-166,共9页
Hydrogeology & Engineering Geology
基金
国家自然科学基金重大项目(41790445)
国家自然科学基金创新性研究群体(41521002)
国家自然科学基金青年基金(41702335)。
关键词
双聚材料
耐崩解性
持水性
生态效应
加固机理
bipoly material
disintegration
water retention
ecological effects
reinforcement mechanism
