Beam B$1$ Is $300mm$ wide by $660mm$ depth with $3$ equal $5$ spans. In the transverse direction, the beams are $4m$ center to center with a $180mm$ thick slab. The live load on the beam $q_k=50k\frac{N}{m}$ and the dead load including self$-$weight $g_k=85k\frac{N}{m}.F_{cu}=30\frac{N}{m}m2,F_y=500\frac{N}{m}m2$ and $F_{yv}250\frac{N}{m}m2.$ Assume mild exposure and $1hr.$ Fire resistance. All columns are $300$ by $300mm.$ Design the beam.

Given:

$b_w=300mm$

$h=660mm$

$h_f=180mm$

$L=5m(continuous)$

$W_{\text{l}\text{i}\text{v}\text{e}}=50k\frac{N}{m}$

$W_{\text{d}\text{e}\text{e}\text{d}}=85k\frac{N}{m}$

$f_{cu}=30\frac{N}{m}{m}^2$

$f_y=460\frac{N}{m}{m}^2$

$f_{yw}=250\frac{N}{m}{m}^2$

mild exposure & $1hr$ fire resistance

columns are $300300mm$