Expansion Bearing
Expansion Bearing
(OP)
I've designed a 75' simple span steel bridge with concrete deck.(Bridge is a private access bridge to a residence) Bridge is supported on grade beam and caissons. One end was detailed with base plate with slotted holes to allow for expansion. Contractor did not use slotted hole bearing plate. My concerns are:
1. Based on 40 degree temp. swing, axial load in steel stringer is about 420 kips. Modeled as a column considering P-delta, beam is no good.
2. Calculated length of expansion is only about .25". This seems minimal and yeilding at the support could accomodate the expansion.
Any thoughts or suggestions?
1. Based on 40 degree temp. swing, axial load in steel stringer is about 420 kips. Modeled as a column considering P-delta, beam is no good.
2. Calculated length of expansion is only about .25". This seems minimal and yeilding at the support could accomodate the expansion.
Any thoughts or suggestions?





RE: Expansion Bearing
So, I don't know why you have them in the first place. Look at the long list of bridges without expansion joints that are longer and have been in service for many years and you see no problems.
I think you need to re-think your system. The caissons should give at least a 1/4" and not even design for temperature.
Run LPile or something and see if the caissons fail with a 1/4" deflection...
MikeD
RE: Expansion Bearing