纳米氧化镁改性黏土强度特性试验  

Experimental research on strength characteristics of nano-Mg O modified soil

作　　者：任真[1,2,3] 余湘娟[1,2,3] 高磊[1,2,3] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学江苏省岩土工程技术工程研究中心,江苏南京210098 [3]河海大学岩土工程科学研究所,江苏南京210098

出　　处：《水利水运工程学报》2016年第5期85-90,共6页Hydro-Science and Engineering

基　　金：国家自然科学基金资助项目(51508159);江苏省自然科学基金资助项目(BK20130832);高等学校博士学科点专项科研基金新教师类资助项目(20120094120015)

摘　　要：为了研究纳米氧化镁对黏性土强度的影响情况,将纳米氧化镁均匀地掺入到黏性土中进行直接剪切试验,并通过扫描电镜试验对剪切面上的微观颗粒进行观察。在含水率分别为10%,16%和22%的情况下,将纳米氧化镁按照0,2%,4%和6%的掺量(质量分数)加入到黏性土试样中进行试验。直剪试验结果表明:当含水率相同时,随纳米氧化镁掺量的增加,纳米氧化镁改性黏土的黏聚力逐渐增大,但是掺量对改性土内摩擦角的影响并不明显;当纳米氧化镁掺量相同时,随含水率增加,改性土的黏聚力呈现出先增后减的趋势,而内摩擦角则逐渐减小。扫描电镜试验结果表明:纳米氧化镁的掺入会降低土体孔隙比,增强颗粒间胶结作用,从而达到改变黏性土剪切强度的目的。In order to study the effects of nano-MgO on clayey soil strength,the nano-MgO was evenly mixed in the clayey soil for direct shear tests,and microscopic particles on the shearing surface were observed by use of the scanning electron microscope tests. Given the conditions that the soil water contents were 10%,16% and 22%,nano-MgO was put into soil samples to carry out experiments with the dosages of 0,2%,4% and 6%. The results from direct shear tests show that when the soil water content was the same,with the increase in nano-Mgo admixture,the cohesive force of the soil samples increased,but the influences of the nano-Mgo admixture on the internal friction angle were not significant; when the nano-MgO admixture was the same,with the increase of soil water content,the cohesive force showed a tendency to increase and then to decrease,while the internal friction angle decreased gradually. The results of SEM show that the nano-MgO admixture can reduce the void ratios of the clayey soil and reinforce the cementation between soil particles,which leads to the changes in the shear strength of the clayey soil.

关 键 词：纳米氧化镁 纳米改性黏土 抗剪强度 扫描电镜 

分 类 号：TU447[建筑科学—岩土工程]