Need a book? Engineering books recommendations...

# steel PL over RC slab

• To: seaint(--nospam--at)seaint.org
• Subject: steel PL over RC slab
• From: Roger Turk <73527.1356(--nospam--at)compuserve.com>
• Date: Tue, 14 Jan 2003 20:49:29 -0500

```Andrew,

The question that you ask is a typical problem in Strength of Materials text
books, at least it was when I went to school and the last time I taught
Strength (more than 20 years ago).  It was used to introduce students to
deformation compatibility as an introduction to solving indeterminate
structures by the method of consistent deformations.

The procedure is to equate deformation of the steel plate *and* the
deformation of the concrete slab.  In the situation that you describe, the
load is applied to the steel plate.  An unknown is the force between the
plate and the slab.

A FBD of the steel plate has the applied load acting down, and an unknown
distributed load acting up.  A FBD of the concrete slab has the unknown
distributed load acting down.  The deflection of the steel plate and the
deflection of the concrete slab has to be equal: deflection of steel plate
due to applied load - deflection of steel plate due to unknown distributed
load = deflection of concrete slab due to unknown distributed load.  Solve
for unknown distributed load.  No FEM or computer or calculator required.
Slide rule helps (G).

HTH

A. Roger Turk, P.E.(Structural)
Tucson, Arizona

Andrew D. Kester wrote:

. > Quick problem, somewhat theoretical:

. > You have a reinforced slab that spans between two beams, in a ribbed slab
. > type of construction. Next place a steel plate continuous over two or more
. > of the spans. The steel plate is not bonded or bolted, just laying on top
. > of the floor. Next pass a moving load from a wheel over this plate. How
. > do you calculate the portion of the load carried by the steel plate and
. > the slab? I don't have any FEA software either. I think there is a
. > somewhat simple solution involving the various EI's of the two materials.
. > In my head I see the steel deflecting under the load, carrying some of
. > the load, then passing the remainder into the slab, until it starts
. > deflecting, then so and so forth until some type of equilibrium is
. > reached.

. > Also is there a way to : a) size the plate so that it carries a specific
. > portion of the load
. > b) the slab carries no load at all, the plate carries all of it

. > I think b) is nearly impossible because you would have to have such a
. > thick plate that it virtually had zero deflection. Noone could transport
. > such a theoretical plate :)

. > Sorry if this is confusing, I am a bit confused but I am sure one of you
. > will clear it up...

. > Thanks in advance,

. > Andrew Kester, EI
. > Longwood, FL

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted
*   without your permission. Make sure you visit our web
*   site at: http://www.seaint.org
******* ****** ****** ****** ******* ****** ****** ********

```