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RE: Fw: pedestrian bridge

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Please explain how the Caltrans specification is misleading.

> -----Original Message-----
> From:	Fredericks, Douglas/SAC [SMTP:DFreder1(--nospam--at)CH2M.com]
> Sent:	Tuesday, March 02, 1999 12:23 PM
> To:	'seaint(--nospam--at)seaint.org'
> Subject:	RE: Fw: pedestrian bridge
> 
> 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
> > > 
> > 
> > 
> 
>