The effect of geocell dimensions and layout on the strength properties of reinforced soil

Selecting suitable materials with acceptable shear strength characteristics may be the easiest and most economical way to obtain the maximum shear strength, if possible. But, it is costly in some projects, due to the long distances to access the source of high-quality materials, as well as environmental constraints. Therefore, this study intends to adopt a more appropriate strategy in order to achieve desired strength properties using 3D geosynthetic reinforcement called geocell. In this study, both laboratory experiments and numerical analyses were employed to investigate the layout-dependent and dimensional effects of geocell on the shear strength of reinforced soil in various sections of a reinforcing element. Experimental outputs were extended using numerical simulation through the finite element method. The results indicated that geocell with smaller pocket opening diameter increased the shear strength of soil up to 31%. It was also observed that despite the increase in the pocket opening diameter (up to 80%), only 4% decrement occurred in the value of shear strength. Due to the increase in the aspect (height-diameter) ratio of geocell, the interface shear strength between the soil and geocell edge increased. When the failure plane exactly passed through the middle of the geocell-height, the shear strength is increased by 11%, in comparison with the state that the edge of geocell is tangential to the failure plane. However, when the geocell moved away from the failure plane, the shear stress-horizontal displacement curves had a similar trend to that of the unreinforced soil.