Abstract：
A rapid growth in the population leads to a large increase in engineering construction. This means there is an inevitability in regard to building on problematic soils. Soil reinforcement becomes an important subject due to the fact that it is a concern for engineers and scientists. With the development of nanotechnology, more and more nanomaterials are being introduced within the practice of soil reinforcement engineering. In this study, the reinforcing effect of novel nanomaterial nano-silica (SiO2) applied to different kinds of soils was systematically studied. The nano-SiO2-reinforced soil possessed lower final water evaporation loss, and evaporation rates. The nano-SiO2 increased the shear strength of clayey soil and sandy soil under both cured and uncured conditions, but the reinforcing effect on clayey soil was more obvious. The addition of nano-SiO2 promotes the friction angle and cohesion of clayey soil; further, it also increases the cohesion of sandy soil. The unconfined compressive strength of clayey soil was enhanced by nano-SiO2, meanwhile, the nano-SiO2-reinforced soil possessed greater brittleness. The microstructure of nano-SiO2-reinforced soil is shown via SEM analysis, and the results of X-ray diffraction (XRD) tests show that there are no new mineral components generated during the reinforcing process. It was also found that nano-SiO2 possessed little influence on the soil pH value. Adding nano-SiO2 will not damage the original chemical environment of the soil. The microstructure of nano-SiO2-reinforced soil was observed to prove the results above. In general, nano-SiO2 is an excellent soil additive that can improve the mechanical properties of both clayey soil and sandy soil effectively. This research provides more ideas and directions for the purposes of selecting soil reinforcement materials.
摘要：
人口的快速增长导致工程建设的大量增加。这意味着在有问题的土壤上进行建筑是不可避免的。由于它是工程师和科学家关注的事实，土壤加固成为一个重要的课题。随着纳米技术的发展,越来越多的纳米材料被引入到土体加固工程的实践中。在这项研究中,系统研究了新型纳米材料纳米二氧化硅（SiO2）对不同类型土壤的增强效果。纳米SiO2增强土具有较低的最终水分蒸发损失，和蒸发率。纳米SiO2在固化和未固化条件下都提高了黏性土和砂性土的剪切强度。但对黏性土的加固效果更为明显。纳米SiO2的加入促进了黏性土的摩擦角和内聚力；进一步，它也增加了砂土的凝聚力。纳米SiO2增强了黏性土的无侧限抗压强度,纳米SiO2加筋土具有较大的脆性。通过SEM分析显示了纳米SiO2加筋土的微观结构。X射线衍射（XRD）测试结果表明，在增强过程中没有产生新的矿物成分。还发现纳米SiO2对土壤pH值的影响很小。添加纳米SiO2不会破坏土壤原有的化学环境。观察纳米SiO2增强土的微观结构以证明上述结果。总的来说,纳米SiO2是一种优良的土壤添加剂，可以有效地改善黏性土和砂性土的力学性能。该研究为选择土体加固材料提供了更多的思路和方向。
