Question

7 Sand, y=18kN/m =38° 1.25ml Sand, y=16kN/m =36° 1.25m GWT clay, Yst=20kN/m 5.0m o=17º; c'=25 kPa; Bed rock A rectangular footing (1.75m x 2.25m) founded on soil profile shown. The footing was designed using the factor of safety equal to 4.0. Determine the punching shear coefficient Ks if the foot in two layers system? * Enter your answer

Answer 1

can consides ecto 2 layers. we 1.25m sard, 8-18kN I h 1.250] 1 2 Top 0:39 TOP sand 2 = 16kN/m? 9-36 3 layer 1-25m] clay Ysat = 20 kN/mi 9 -17°, c': 25kpa res Bolton layer Top layer ultimale beaning capail; 197 = CN[ + qNq T. PR ND = 1 8X2.5X61.55 + 0-5 X 18 X 1.75 x 786) 2 Bottom CNet + 0.5VBN, = 4007.85 kN/m layer 92 = 14.6x25 + ((90-10) X5X5-45)+0.5x10x = 656.575 kN/m + & Pf Nr 1.25*2.18)

Punching shear coefficant, ovela = 656.575 4007.85 = 0.1621 Top layer is strenger soil Foss From the meyer ay shof chart purching = 2.4 shear coeffinert, ks 194/9, +0:16,9=56]