P$=49$ kips

L$=114\text{'}$

I$\text{'}$d like to use ASTM$-$A$709$ Grade $100$ structural steel as the material

Assume there was a "mis$-$hap" on the bridge truss below where a tug boat pulled a tall barge through the

bridge and damaged it beyond repair. The town residents aren't very impressed that they can't get across

state lines to buy their summer fireworks. The Department of Transportation wants a temporary fix while

they consider options for removal and replacement of the bridge; or a combined repair and retrofit.

You are tasked to work with a local steel fabricator to size a beam to span the gap and get the road

opened as soon as possible. The original truss loading is shown below $($acts on each truss$).$ Convert this

loading to a line load and select a beam shape and material for the span.

Document each step and decision in your calculations.

Keep in mind that a minimum of $2$ beams is required, but more are optional.

At the end of your calcs, identify two failure modes that this design doesn't consider, which you will learn

in subsequent classes.

Figure $1-$Middle span