Abolfazl Soltani - Associate Professor, Faculty of civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran,
Amin Moradi - Master in Geotechnics, Faculty of civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
Nabiollah Ahmadi - Master in Geotechnics, Faculty of civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran

Improving the geotechnical properties of soil with nano materials is a new method forstabilizing the unstable clay soils. There is various type of industrial nano materials which areknown as soil-additives in geotechnical proposes. Nano materials are different in microstructure, crystal shape and chemical capability, causing variation in performance of the soilsto be stabilized. The geotechnical tests carried on samples treated by nano particles indicatethat multi wall carbon nano tubes (MWCNTs) and carbon nano fibers (CNFs) are essentialadditives for improving the physical properties of unstable soils including Atterberg limits,optimum moisture content and maximum dry density. Small amount of nanosilica andnanokaolinite particles increased the maximum dry density and UCS results but a reversetrending in optimum moisture content is observed in which nano silica treated the soil towardsthe higher water contents. In contrast, nanokaolinite showed higher positive influence on thestiffness of treated specimens using a significant amount of lower water absorption. Majordifference between the performance of all the studied nano particles includes that nanomontmorillonite reduced the dry density of soil as the ꞷ% increased.

soil stabilization, nanosilica, nanokaolinite, geotechnical properties