b) bearing strength of concrete =0.6$\times$fck =0.6$\times$15=9mpa

M15-fck=15

Required-welded gusseted base

1) AP=$\frac{pu}{0.6\times15}=\frac{1700\times10^{3}}{0.6\times 15}$

Ap=183.89$\times 10^{3}mm^{2}$

2) width of base plate(Bp)=350+2(16)

Bp=382mm

Assume gusset plate 16mm$\gt$tf

16mm$\gt$11.6 safe

overhange=$\frac{450-382}{2}$=34mm

Bp=350+2(16)+2(34)

Bp=450mm

3) Lb=$\frac{Ap}{Bp}=\frac{188.89\times10^{3}}{450}$=419.76mm

Lp=430mm

Step II. Thickness of base plate

Bmxx=$\frac{wl^{2}}{2}$ L=50 w= $\frac{pu}{AD}=\frac{1700\times 10^{3}}{450\times 436}$

W=8.885mpa

8.87$\lt0.6\times$fck …