I agree that the references given by Jim Kestner are valuable. I have used
the approach many times for design. Since the references are old and may be
difficult to find may I suggest you refer to Chapter 17 of Reinforced
Concrete Fundamentals by Phil M. Ferguson, published by John Wiley & Sons.
Merrill Walstad S.E.
Huntington Beach, CA
----- Original Message -----
From: "Jim Kestner" <jkestner(--nospam--at)somervilleinc.com>
Sent: Monday, April 17, 2000 9:29 AM
Subject: Re: Payloader Slab Design
> Westergaard produced a number of useful graphs for determining moments
> produced by concentrated loads for the Bureau of Public Roads in the
> 30's. Included is positive moments in both directions for simple and
> fixed spans as well as overlapping effects for multiple loads and
> negative moments produced by a concentrated load near an interior
> Spangler produced a study that gave a methodology for determining the
> effective width for shear.
> I believe the information in AASHTO is based on Westergaard's work. I
> find that these original works are extremely useful (and easy to apply)
> for the engineer who designs buildings, since they are not in terms of H
> and HS loadings and contact areas.
> I recommend that you obtain copies from your local library.
> The articles are as follows:
> Computation of Stresses in Bridge Slabs Due to Wheel Loads by H. M.
> Westergaard, March 1930, Vol. 11, No. 1, Public Roads
> The Distribution of Shearing Stresses in Concrete Floor Slabs Under
> Concentrated Loads by M. G. Spangler, April 22, 1936, Bulletin 126, Iowa
> Engineering Experiment Station
> Jim Kestner, P.E.
> Green Bay, Wi.