| 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。 |
| 关键词: 纳米氧化镁 纳米改性黏土 抗剪强度 扫描电镜 |
| DOI： |
| 分类号:TU447 |
| 基金项目: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） |
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| Experimental research on strength characteristics of nano-MgO modified soil |
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REN Zhen1,2,3, YU Xiang-juan1,2,3, GAO Lei1,2,3
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1.Key Laboratory of Geomechanics and Embankment Engineering of Ministry of Education, Hohai University, Nanjing;2.Jiangsu Research Center for Geotechnical Engineering Technology, Hohai University, Nanjing;3.Geotechnical Research Institute, Hohai University, Nanjing
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| Abstract: |
| 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. |
| Key words: nano-MgO nanometer modified soil shear strength SEM |
