Calculation for Grade of Geogrid in Replacement zone

For, RE Wall height = 7.6m

Mayerhof stress σv   = 201.43 kN/m2 , taken as per design report, Load Case C

 σh = σv x K, where k is coeff. of earth pressure, Ka= 1-sin(phi)/1+sin(phi), take phi = 30

Ka = 0.333

σh = 201.43 x 0.333 = 67.076 kN/m2

Depth of replacement = 1.9 m (Including Two layers of Geogrid at centre of Replacement)

So, hz force on complete thickness of replacement = 1.9 x 67.076 = 127.44 kN/m2

on apply FOS, 1.5 

therefor, 127.44 x 1.5 = 191.16 (this is resist by geogrid)

Including Two layers of Geogrid at centre of Replacement = 191.16/2 = 95.589 kN/m2

Grade of Geogrid by using Material coefficient = 95.58 x 1.1x 1.05 x 1.47 = 162.28 kN/m2

Therefor Grade of Geogrid = 162.28 kN/m2 which is equivalent to GG-200