PROBLEM $3\mathrm{.}3$:

A footing supports a $300$ mm thick concrete wall which carries an axial loads and moments as

indicated below.

Axial Load: $P_{DL}=200k\frac{N}{m},P_{LL}=180k\frac{N}{m}$

Moment: $M_{DL}=30kN\frac{m}{m},M_{LL}=50kN\frac{m}{m},M_E=60kN\frac{m}{m}$

The thickness of the wall footing is $500$ mm with an effective depth of $430$ mm $.$ The bottom of the

footing is $1\mathrm{.}20$ m below the ground surface. Unit weight of soil $=15k\frac{N}{m^3},$ unit weight of concrete

$=23\mathrm{.}45k\frac{N}{m^3},f_c^{\text{'}}=20\mathrm{.}7$MPa,$f_y=415$MPa. The allowable soil bearing pressure is $200$ kPa $.$

Use NSCP $2015$

a Determine the width of the footing:

Ans: $3\mathrm{.}491m$

b$.$ Determine the nominal shear stress at the critical section.

Ans: $0\mathrm{.}720$ MPa

c$.$ Determine the design moment.

Ans: $256\mathrm{.}120$ kNm