纳米硅基固沙材料加固机理及抗冲蚀试验研究

An experimental study of the reinforcement mechanism and erosion resistance of nano silicon-based sand-fixation material

为了减少荒漠化地区沙坡在降雨冲蚀作用下坡体坍塌、水土流失的发生,以西藏雅鲁藏布江河谷分布的沙质边坡为研究对象,提出采用自主研发的纳米硅基固沙材料(nano-silicon/polymer composites,NSPC)对沙坡坡面进行防护。针对NSPC固沙材料加固沙体作用效果尚不明确,基于红外光谱、黏度测试、接触试验以及模拟沙坡降雨冲蚀试验,探讨NSPC固沙材料加固沙体的作用机理,研究降雨作用下NSPC固沙材料加固沙体的抗冲蚀能力。试验结果表明:NSPC固沙材料与沙粒通过聚合、胶结作用相互交叉缠绕、联结形成立体网状结构,从而达到加固沙体的目的;NSPC固沙材料的流变性在初始1 h内属于宾汉流体,后期逐渐转变为牛顿流体;NSPC固沙材料表面张力为60.31 mN/m,与沙体接触角为48.6°,黏附力为0.040 N/m,因此具有较强的入渗能力;沙坡表面形成的加固层对雨水冲蚀具有较强的阻滞效果,并且加固层还具有一定的保水能力。本研究可为NSPC固沙材料在荒漠化地区固沙防护工程中的应用及推广提供试验支撑。

To reduce the slope collapse and soil erosion under the action of rainfall erosion in desertification areas,the self-developed nano silicon-based sand-fixation material(Nano-Silicon/Polymer Composites,NSPC)is proposed to protect the sandy slope surface of the Yarlung Zangbo River Valley in Xizang.In view of the unclear effect of NSPC sand-fixing material on strengthening sand body,based on infrared spectrum,viscosity test,contact test and simulated sandy slope rainfall erosion test,the mechanism of NSPC sand-fixation material to strengthen the sandy slope is discussed,and the anti-erosion ability of the NSPC sand-fixation material under the rainfall is studied.The results show that the NSPC sand-fixation material and sand particles cross and intertwine with each other through polymerization and cementation to form a 3D network structure,so as to achieve the purpose of strengthening the sandy body.The rheological properties of the NSPC sand-fixation material belongs to Bingham fluid in the first 1 h,and gradually changes to Newton fluid in the later period.The surface tension of the NSPC sand-fixation material is 60.31 mN/m,the contact angle with sandy body is 48.6°,and the adhesion force is 0.040 N/m,therefor it has strong infiltration ability.The reinforcement layer formed on the sandy slope surface has strong blocking effect on rainwater erosion,and the reinforcement layer also has water retention ability.This study provides test support for the application and promotion of the NSPC sand-fixation material in sand fixation and protection projects in desertification areas.