PROBLEM $9\mathrm{.}3$:

A $600mm600mm$ column by a $3\mathrm{.}6$ m square footing on $5$ piles as shown.

Effective depth $=650mm$

Diameter of pile $=350mm$

Ultimate pile capacity $=280kN$

Column axial loads:

Column axiar

$D=420kN,L=360kN,E=210kN$

Column moment due to earthquake $=160kNm$

Required Strength of the footing is based on:

$y=1\mathrm{.}32D+1\mathrm{.}1L+1\mathrm{.}1E$

a$.$ Compute the critical beam shear stress at ultimate loads.

Ans: $0\mathrm{.}311$ MPa

b$.$ Compute the ulimate punching shear stress.

Ans: $0\mathrm{.}291$ MPa

c$.$ Compute the nominal punching shear stress of the most stressed pile.

Ans: $0\mathrm{.}178$ MPa