Approach Slab Omission from Bridge
Approach Slab Omission from Bridge
(OP)
We have a bridge located inside a county park and will have very low daily traffic. The G.C. just got bids for the bridge and they are higher than expected. We are looking at ways to cut costs. One idea is to remove the approach slabs, which are a big cost item for this small single span bridge. Does anyone have a good resource showing what type of subgrade should be placed under the asphalt at the bridge interface to help prevent settlement between the asphalt surface and the bridge?
Thanks!
Thanks!






RE: Approach Slab Omission from Bridge
I don't think you can ever avoid settlement completely. This would become an on-going maintenance cost vs. the up-front one time cost of the approach slab.
The amount of traffic wouldn't change anything - the settlement occurs due to the build-up of the grade at the bridge end...i.e. the soil self-weight creates long term settlements.
RE: Approach Slab Omission from Bridge
RE: Approach Slab Omission from Bridge
Other options are to preload the fills to accelerate any settlement that may be expected thereby minimizing.
Another option that is becoming frequent is to use a slab on grade as the approach slab rather than a one slab supprted on the pavement notch (abutment) and sleeper slab. This reduces the amount of reinforcing greatly.
Regards,
![[pipe] pipe](https://www.tipmaster.com/images/pipe.gif)
Qshake
Eng-Tips Forums:Real Solutions for Real Problems Really Quick.
RE: Approach Slab Omission from Bridge
Do you have any links with any white paper or other write-ups on this? I want to be able to provide the owner with examples that other DOT's are doing this.
Thanks!
RE: Approach Slab Omission from Bridge
Here's an example result I found...
h
Regards,
![[pipe] pipe](https://www.tipmaster.com/images/pipe.gif)
Qshake
Eng-Tips Forums:Real Solutions for Real Problems Really Quick.
RE: Approach Slab Omission from Bridge
RE: Approach Slab Omission from Bridge
Would that be a possible replacement for structural fill in some applications? I'm thinking it might be more suited for stub abutments than high abutments due to the need to contain it, higher cost than structural fill, etc.
Maybe the tyranny of Murphy is the penalty for hubris. - http://xkcd.com/319/
RE: Approach Slab Omission from Bridge