Hi, I have to design a steel structured truss footbridge.(adsbygoogle = window.adsbygoogle || []).push({});

Im using beam anology to determine the correct member sizes.

Having trouble determining the maximum design moment (M*)

Here's what I have calculated thus far:

Q=6kN/m

G=1kN/m

50m long, 3m depth, 3.125m spacing

Self Weight Preliminary Design

Chords :150UC30.0

Tension-Web :90x90x6EA

Comp-Web :150PFC

therefore SW=4.48kN/m

W*=1.2(1+4.84)+1.5(6)

W*=16/2

W*=8kN/m per truss

M*=2500/3m depth

N*=833kN

After trial and error, all satisfy N*<Nt,Nc

Chord :200UC46.2

Tension-Web :125x125x12EA

Comp-Web :380PFC

From this point onwards, how do I solve for M*<Mb?

And do I solve M*<Mb individually for all members?:

M*<Mb,200UC46.2

M*<Mb,125x125x12EA

M*<Mb,380PFC

??

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# Design of steel truss footbridge

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