Re: Lateral Stability of a Box Beam ?

Mr Ransom,

 

What are simple ties by the way? Did you mean pin-pin connection for the bracing members? If so, why not consider the "ladder" as a parallel-chord truss? Do not truss transfer shear? Plywooded trusses are even better  -- consider them as a horizontal shear wall.

 

Can compare with the laced and battened columns and struts that we see in old steel bridges. British steel code used to have a detailed method of designing laced and battened members to carry axial and bending. How about Australian code, Mr. Conrad?

 

 

Bill was asking for a method of designed boxed beams. Nobody here is arguing that boxed beams has no benefit. I am not sure what point you are trying to make here.

 

 

 

> -----Original Message-----
> From: Paul Ransom [mailto:ad026@hwcn.org]
> Sent: Sunday, 18 January 2009 06:54
> To: seaint@seaint.org
> Subject: Re: Lateral Stability of a Box Beam ?

> If the 2 beams are identical with identical loading, there is no benefit to
> simple ties. Unless there is some shear resistance mechanism between the
> brace points, the unbraced length for lateral buckling is not reduced and
> the ladder simply behaves like 2 tied beams (e.g. Iy1 + Iy2) and they just
> displace in unison.

 

 

 

 

> Regards
> Paul
> --
> Paul Ransom, P.Eng.
> ph 905 639-9628
> fax 905 639-3866
> ad026@hwcn.org