YOU ARE THE ENGINEER OF RECORD. Can you accept this? In highway bridge
design the bearing pads allow for the superstructure to slide into the back
wall. The pads are a soft spring at each roller, this is acceptable but the
abutment acts as a large locking seat and the structure has no where to go.
In your bridge will the bolts shear off before the structures loads another
structure system(back wall-shear key)? you must design for the movement.
From: Vyacheslav Gordin [mailto:scgordin(--nospam--at)hotmail.com]
Sent: Saturday, June 19, 1999 7:04 AM
Subject: Bridge Problem?
The manufacturers of the light vehicular and/or pedestrian truss steel
bridges provide slotted holes in the baseplates on BOTH ends of the bridge.
That effectively means that the longitudinal earthquake load is resisted by
the joint between the bridge deck and abutments.
The manufacturers's engineers (PE) claim "standard practice." Indeed, I
checked several designes - they basically are the same. Can we accept the
concept of a beam with BOTH roller supports?
Vyacheslav "Steve" Gordin, SE
Get Free Email and Do More On The Web. Visit http://www.msn.com