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Derivation of Flamant’s Equations for the Elastic Response Under a Strip Load

In the last post I showed the derivation of the elastic response of a soil to a point load using Boussinesq theory. This is a common part of elementary Soil Mechanics courses but it is uncommon to see the derivation.

The same situation exists with strip (continuous) foundations, the elastic solution usually attributed to Flamant. The solution itself also presented in NAVFAC DM 7.01 and Arnold Verruijt’s Soil Mechanics. The derivation is presented below, and comes from the Manual of the Theory of Elasticity, by V.G. Rekach. Some discussion of this solution is in my post Analytical Boussinesq Solutions for Strip, Square and Rectangular Loads and my class presentation is at Soil Mechanics: Elastic Solutions to Soil Deflections and Stresses.

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In Memoriam: GZA Founder Donald T. Goldberg — GeoPrac.net

His contributions and legacy are reflected in the values of the company he built and the leadership he provided to the industry he loved. President and CEO Patrick Sheehan reflects on Don’s legacy. “It would be […]

In Memoriam: GZA Founder Donald T. Goldberg — GeoPrac.net

Since 2004 this site has hosted Goldberg’s classic document Lateral Support Systems and Underpinning.

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Our Anniversary, and the Web in the 1990’s

On this day in 1997 this website was started as a GeoCities site.  Wonder what the web was like back then?  This video is a nice quick summary of that time, both this site and the net have come a long way–for better and worse–since that time.  (It also explains what it meant to be a GeoCities site, too.)

Readers of this blog will know that my family goes back a long way visiting the Bahamas in general and the Abaco Islands in particular. We had some exciting times, almost sending our ship to the bottom and riding out a storm. This beautiful paradise, which looked like this when we visited: Now looks like […]

via Appeal for the Abaco Islands, and Mercy Chefs — Chet Aero Marine

Appeal for the Abaco Islands, and Mercy Chefs — Chet Aero Marine

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Argument from authority

The Logical Place

by Tim Harding

The Argument from Authority is often misunderstood to be a fallacy in all cases, when this is not necessarily so. The argument becomes a fallacy only when used deductively, or where there is insufficient inductive strength to support the conclusion of the argument.

The most general form of the deductive fallacy is:

Premise 1: Source A says that statement p is true.
Premise 2: Source A is authoritative.
Conclusion: Therefore, statement p is true.

Even when the source is authoritative, this argument is still deductively invalid because the premises can be true, and the conclusion false (i.e. an authoritative claim can turn out to be false).[1] This fallacy is known as ‘Appeal to Authority’.

The fallacy is compounded when the source is not an authority on the relevant subject matter. This is known as Argument from false or misleading authority.

Although reliable…

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