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EPART SIXAppendix EAASHTO LRFD METHODOLOGY LEVEL SURCHARGE - 250 PSF11) Bearing CapacityEquation (3k)Q ult = cN c +γDN q +0.5γ(B-2) Nγwhere:N c = 30.14, N q = 18.4, Nγ =22.40B = (B-2e) = (9.0'-2 x 0.86) = 7.28'D = 1.0' level embedmentc = 0Q ult = 0+(120)(1)(18.4)+(0.5)(120)(7.28)(22.40)= 11992 psfCDR br RF br (Q ult /σ v )CDR dr = 0.65 (11992/2484) = 3.14 > 1.0 OKInternal Stability - The internal analysis must look at the maximum loads at each grid level,connection strength, pullout resistance, and local stability concerns:q for maximum stress, bearing pressure3XTZ3XTH=10'3XT3XTσ EVd qhσ EVd ah3XT1.0'8.0'B = 9.0'The internal earth pressure at any level is calculated as follows:σ ah = EV d γ Z k a cos (β)= (1.35)(120pcf) (Z) (0.283) Cos (0)= 45.5 (Z) plfσ qh = EV d qk a Cos (β)= (1.35)(250psf) (0.283) Cos(0)= 95.5 plfThe calculated pressure is applied to the tributary area of each reinforcement level which determinesthe tensile load in the geogrid reinforcement.E.6