Question

3)If the same footing in the same sand is to be designed by using the results of the SPT test performed at the location of the footing, calculate the allowable bearing capacity. The SPT test gave gave an uncorrected SPT number N=28 at the level of the base of footing. The total settlement is to be limited to 25 mm. The SPT was performed in a 200 mm borehole with a hammer efficiency, 0.45 and a standard sampler was used. Relative density of sand is Dsa=0.4 mm. The ground water level is at a depth of 6 meters. Calculate the bearing capacity based on SPT results. (Hint:Find Niso) and use the empirical equation, G=(0.41)(NL)50[S:), where s is the allowable total settlement in milimeters.)

Answer 1

NOWOTWINNI Roaring capacity ; Pa = 0.41 (N)S N, =correcked spt NO: N = -350 XN (340) 5+10 5=E ffective over over bueden pressure 3Q Knim? Ni 350 28 ) 32 +70 = 96 Hercer coaker table is not encountered at the location q keshing need oq dilatancy correction Sono Recaping capacity; la = 0.41x96x25 = 984.8 knim?