In recent years, reinforced technique has been widely used in civil engineering technology. order to deeply understand the behavior of structure, this paper use geogrid as materials. The unconfined compressive tests were operated laboratory. specimens made by sharp sand which was classified according density at ρ=1.55g/cm3, ρ=1.75g/cm3, ρ=1.85g/cm3.Each specimen with layers 0,1,2,3,4,5. Through...