KL=0.85L=0.86$\times$3000=2550mm

$\lambda=\frac{kL}{\gamma min}=\frac{2550}{18.2}$=140.11

$\lambda$ $\ \ \ \ \ \ \ \ $ 250mpa

140 $ \ \ \ \ \ $ 66.2

140 $ \ \ \ \ \ $ fcd

150 $ \ \ \ \ \ $ 59.2

fcd=66.123Mpa

PD=A prov $\times$ fcd=1368$\times$66.123

=90.46kN $\lt$19.69kN

safe in compression

provide 2 ISA 60$\times$ 60$\times$6mm at a tie member with2-16mm $\phi$ boltas as end conn