纳米SiO_(2)和石灰改良黄泛区粉土的力学特性研究  

MECHANICAL PROPERTIES OF NANO-SiO_(2) AND LIME-STABILIZED SILT IN YELLOW RIVER FLOOD AREA

作　　者：张艳美 马丁 李国勋 毕舰心 ZHANG Yanmei;MA Ding;LI Guoxun;BI Jianxin(College of Pipeline and Civil Engineering,China University of Petroleum(Huadong),Qingdao 266580,China;State Grid Shandong Electric Power Company,Binzhou 256610,China)

机构地区：[1]中国石油大学储运与建筑工程学院,青岛266580 [2]国网山东省电力公司,滨州256610

出　　处：《工程地质学报》2021年第4期1233-1239,共7页Journal of Engineering Geology

基　　金：国家自然科学基金(资助号:51208510);山东省研究生教育质量提升计划项目(资助号:SDYAL17020);山东省研究生教育创新计划项目(资助号:SDYY15140)。

摘　　要：为探究纳米SiO_(2)和石灰对黄泛区粉土的改良效果,通过击实试验、无侧限抗压强度试验、扫描电镜试验和XRF试验等系列试验,研究纳米SiO_(2)和石灰掺量对黄泛区粉土压实性、抗压强度、水稳性等力学特性的影响,分析改良粉土的微观结构及固化机理。结果表明:纳米SiO_(2)改良土的最大干密度和最优含水率随纳米SiO_(2)掺量的增加而提高,纳米SiO_(2)改良土中掺加石灰会降低最大干密度,但会提高最优含水率;纳米SiO_(2)与石灰联合使用改良效果优于单独掺入纳米SiO_(2),1.5%纳米SiO_(2)-2%石灰改良土的无侧限抗压强度、黏聚力和内摩擦角提升最为显著;与素土和纳米SiO_(2)改良土相比,纳米SiO_(2)-石灰改良土的水稳性得到显著改善;在纳米SiO_(2)改良土中,纳米SiO_(2)主要起到填充土颗粒之间孔隙的作用,纳米SiO_(2)与石灰联合使用可在土中形成胶结物质、发挥黏结与填充作用、大幅提高土的强度。In order to explore the improvement effect of nano-SiO_(2) and lime on silt in the Yellow River flood area,a series of tests including compaction test,unconfined compressive strength test,scanning electron microscope test and XRF test were conducted.This paper aims to study the effects of nano-SiO_(2) and lime content on the compaction characteristics,compressive strength,water stability of silt.The microstructure and improved mechanism of the stabilized silt were analyzed.The results show that the maximum dry density and the optimum water content of the stabilized silt increase with the addition of nano-SiO_(2) content.The addition of lime in the nano-SiO_(2) stabilized silt reduces the maximum dry density,but increases the optimal water content.The combined improvement effect of nano-SiO_(2) and lime is better than that of nano-SiO_(2) alone.The unconfined compressive strength,cohesion and angle of internal friction increase most significantly.Compared with pure soil and nano-SiO_(2) stabilized silt,the water stability of nano-SiO_(2)-lime stabilized silt is significantly improved.In the nano-SiO_(2) stabilized silt,the nano-SiO_(2) mainly serves to fill the pores between the soil particles.The combined application of nano-SiO_(2) and lime can form cementing material in the silt,play a role of bonding and filling,and greatly improve the strength of the silt.

关 键 词：纳米SiO_(2) 石灰 黄泛区粉土 力学特性 微观结构 

分 类 号：TU433[建筑科学—岩土工程]