Culvert extension settlement analysis
Culvert extension settlement analysis
(OP)
I have never performed culvert settlement analysis before. I will have (4-foot to 8-foot) box culverts and (36-inch to 54-inch) pipes (RCP and CMP). My predecessor assumed 75%-full culverts and wrote up recommendations to limit settlement to one inch. He/she also neglected wheel loads. It all seems easy enough, but that is what makes me nervous. I am asking for lessons learned, if anyone is willing to provide.





RE: Culvert extension settlement analysis
I am thinking that if there is a road already at the site, a culvert may actually unload the site (from the void in the culvert). From culverts that I have seen, the culvert would cause some settlement, but the majority would come from the backfill covering the culvert.
Hope this helps, others can provide better guidance.
- EIT Geotechnical Engineer. I am here hoping to help, and learn a little along the way.
RE: Culvert extension settlement analysis
On the topic of lessons learned: Don't forget internal drainage. Consider enveloping the lower 1/3rd of the culvert structure with a bedding layer of gravel and the sidewalls also! That way, seepage forces acting along the interface of the culvert concrete and the bearing soil/culvert backfill will be protected from piping failure.
Hope some of this helps. Some of this is common sense, other then the structural design of the sidewalls and base slab.
f-d
¡papá gordo ain't no madre flaca!
RE: Culvert extension settlement analysis
I will be looking into the cradle option today (I don't know yet if the original culverts were installed on cradles or not and how the difference would be good or bad.)
There's a FEMA Technical Manual about "conduits" through emabnkment dams that had some interesting points about over-compaction around structures and erosion in case anyone else is interested. http://www.fema.gov/library/viewRecord.do?id=1827
I think I'm comfortable with my approach, now. Thanks so much for responding. Of course, feel free to continue to pass anything along. Report isn't due until Friday :)