Non-linearity on pull-out test of cohesive soil using low tensile strengths of geogrids

Influence of geosynthetics inserted into cohesive granular soil was obviously investigated using geosynthetics-soil-interaction-testing device (ITD). Observations were already made during undertaking pull-out test, and then the results revealed that a correlation between shear stress and normal stress exhibits non-linear behaviour. In this paper, three approaches of trend-lines namely linear, logarithmic, and polynomial were compared. From analysis, polynomial trend line gave the best correlation among others. The final equation is very important part when estimating more accurate values of cohesion and friction angle design purpose.