Design of geocell stakes along slopes using analogy of laterally loaded piles

Geocells with low aspect ratio are recommended to prevent erosion of slopes of soil embankments. Steel stakes / pins are generally used to hold these geocells in position. Generally anchor stakes are designed for pullout; however this procedure is inappropriate where in-filled geocells placed along a slope are subject to net sliding forces along the slope in a direction perpendicular to the anchored stake. A close similarity can be drawn to laterally loaded piles. Anchor stakes normally used are 8mm diameter mild steel rods, 450mm length. By a thumb rule, the anchor stake length should be at least thrice the depth of geocell. However diameter of the stake as well as embedment length and spacing of the stakes will depend upon several factors, primarily the undrained shear strength of the embankment material, besides the density of the in-fill material and weld spacing of the geocells which would manifest as net sliding forces. This Paper considers the net sliding forces parallel to the slope and provides a mechanistic approach to the analysis to determine the adequacy of the embedment length of the stake and as a corollary, the number of stakes required to take up the net sliding forces, limiting the deflection of the stakes and thereby limiting deflection of the geocell sysyem down the slope. The analysis deliberated here is analogous to laterally loaded long piles.