APPLICATION OF MULTI-WALLED CARBON NANOTUBES IN SLOPE STABILIZATION

Abstract

Landslides are a common phenomenon that every year causes economic and human losses around the world. It emerges in various geographical places worldwide because of diverse natural circumstances and triggering mechanisms, including precipitation, seismic events, and anthropogenic interventions. In the conventional methods, slopes are stabilized using different methods including application of lime, cement, and fly ash. However, each of these materials has their own shortages. In this study, the application of multi-walled carbon nanotubes (MWCNT) is investigated for slope stabilization. Extensive tests are conducted in the laboratory to obtain the index properties, compaction, soil water characteristics curve and unsaturated permeability of the soil for both scenarios of soil with and without MWCNT. Liquid limit and plastic limit of soil stabilized with MWCNT increased compared to soil without multi-walled carbon nanotubes and plasticity index decreased. The result from SWCC demonstrates that saturated volumetric water content and air entry value of the soil with MWCNT has increased compared to soil without MWCNT. The result from unsaturated permeability test demonstrated that the unsaturated permeability of soil stabilized with MWCNT has decreased. Different sets of numerical analysis were conducted using Seep/W and Slope/W to analyze the seepage and safety factor of slope with and without MWCNTs. The result from Seep/W analysis shows that the pore water pressure (PWP) in the slope without carbon nanotube is lower than PWP in the slope with MWCNT in the surface area. Moreover, it shows that the PWP in the surface area is increasing by passage of time during the rainy period and it is decreasing as the raining period stops. The result from slope /W analysis shows that factor of safety (FoS) of slopes without MWCNT. However, the FoS of slope MWCNT declines rapidly and with a high rate, while the FoS of slope with MWCNT only change slightly and remains safe compared to non-stabilized slope.