$6-8$ The beam shown in Fig. P$6-8$ supports the unfactored loads shown in the figure. The dead load includes the weight of the beam.

a$.$ Draw shearing$-$force diagrams for

factored dead and live load on the entire length of beam,

factored dead load on the entire beam plus factored live load between $B$

$278$

and $C,$ and

factored dead load on the entire beam plus factored live load between A and $B$ and between $C$ and $D.$ Loadings $(2)$ and $(3)$ will give the maximum positive and negative shears at $B.$

b$.$ Draw the factored shear$-$force envelope.

c$.$ Design shear reinforcement. Use $f_c^{\text{'}}=5000$ psi and $f_{yt}=40,000$ psi.

Fig. P$6-8$