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RE: Fw: pedestrian bridge

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The way I read the AASHTO code, Group IH would be 1.3*(DL+1.67LL), where LL
is 85 psf.  Impact is not applied to pedestrian live loads.  Note that the
Caltrans code has a misleading description of loads for pedestrian bridges
(3.14.1.3).

Looking at the AASHTO LRFD code clears this up.  Pedestrian live load is
85psf (case PL) and it gets a 1.75 load factor. The code specifically states
that impact is not applied to pedestrian loads (3.6.2.1).

Also, AASHTO has produced a pedestrian bridge guide specification.  They
give a service live load of between 85 and 65psf depending on floor area.
It is not a LRFD code so there aren't load factors.  This code doesn't
specifically mention Impact, but an example is provided in which impact is
not applied.

(They provide some guidance on vibrations as well.)

> -----Original Message-----
> From:	Powers, Tony [SMTP:tpowers(--nospam--at)hdrinc.com]
> Sent:	Thursday, February 25, 1999 9:12 AM
> To:	seaint(--nospam--at)seaint.org
> Subject:	RE: Fw: pedestrian bridge
> 
> Just to confuse the issue a little more, AASHTO Section 3.14.1.3 specifies
> a
> live load of 85 psf for pedestrian bridges.  Where maintenance vehicles
> are
> expected, Section 3.14.1.4 says that these should be considered separately
> -- an H10 truck (1/2 of an H20) is sometimes used. Caltrans goes further
> and
> specifies that Impact should be included for load group IH with BetaL=1.0
> (this is normally 1.67) and, if you happen to have equestrians, Caltrans
> specifies that the bridge be checked for an H10 truck.  So, now you have
> three loads.  AASHTO/Caltrans includes an impact factor, which might
> account
> for the difference between their 85psf and UBC's 100 psf.
> 
> 
> > -----Original Message-----
> > From:	Jill T. Shuttleworth, P.E. S.E. [SMTP:andeng(--nospam--at)televar.com]
> > Sent:	Thursday, February 25, 1999 8:20 AM
> > To:	seaint(--nospam--at)seaint.org
> > Subject:	Re: Fw: pedestrian bridge
> > 
> > The 1997 UBC recommends 100 psf for pedestrian bridges Table 16-A.  In
> > Table 16-B Construction walkways are 150 psf.  Does someone know why
> there
> > is a discrepancy in these two loads? 
> > 
> > Jill T. Shuttleworth, P.E., S.E. 
> > Sunnyside, WA 
> >   
> > 
> > prosteel wrote: 
> > 
> > 	  what live load should be used for a pedestrian bridge spanningup
> > to 210 ft. in some cases, light vehichles may pass rauf akbaba
> > 
> 
>