From: Roger Turk <73527.1356(--nospam--at)compuserve.com>
Date: Wed, 23 Jun 1999 12:26:48 -0400
Chris Towne wrote:
. > I take it that there are not that many bridge engineers on this list.
Oh, I wouldn't say that!
Like any other beam/girder that has uplift at a support, you have to tie it
down. The means of accomplishing this is as varied as twice the number of
engineers that you talk to.
Typically, uplift at an abutment will occur only when you have a very short
end span in a continuous structure. For balancing of moments, the span
ratios should be of the order of:
What I am trying to figure out is what is a, "semi-integral" abutment?
If you are considering using an integral abutment, the bridge should have
*no* skew. If there is skew, it should be recognized that the abutment will
be very flexible perpendicular to the abutment and very stiff along the
abutment. Thermal movement of the deck will cause the abutment to try to
move in a direction parallel to the girders, but the abutment will want to
move perpendicular to the abutment, and has to be forced to move in a
direction parallel to the girders. Failing to consider this can result in
distress in the abutment or in the deck (longitudinal cracking over the
A. Roger Turk, P.E.(Structural)