3 Single Precast Box Culverts
3 Single Precast Box Culverts
(OP)
I am designing 3 single precast box culverts that will be placed side by side with variable gaps between them from 3" to 1'-7" depending on fill and varying wall thickness. The question asked by DOT engineers is would the lateral pressure be different on interior walls from exterior walls if the gaps are filled with porous gravel?





RE: 3 Single Precast Box Culverts
Mike Lambert
RE: 3 Single Precast Box Culverts
RE: 3 Single Precast Box Culverts
RE: 3 Single Precast Box Culverts
www.PeirceEngineering.com
RE: 3 Single Precast Box Culverts
You are correct sir!
RE: 3 Single Precast Box Culverts
If it were me, I would place concrete, flowable fill if I couldn't get concrete, between the culverts instead of gravel. That way you know the water will stay in the culverts and that the sides of the culverts are adequately supported.
Mike Lambert
RE: 3 Single Precast Box Culverts
www.PeirceEngineering.com
RE: 3 Single Precast Box Culverts
I'm a design engineer for a DOT. I've laid out numerous multiple barrel precast box culvert installations, and I've never been asked by any of the precasters who do the designs for our culverts what we were putting between them. I fail to see how it could possibly matter.
Just as an aside, we typically put them an inch apart with a cement slurry in the gap.
RE: 3 Single Precast Box Culverts
with intimate contact between the boxes, statics would require loads be conveyed from one to the other.
Let's just leave it at that for now.
kind regards,
f-d
ípapß gordo ainÆt no madre flaca!
RE: 3 Single Precast Box Culverts
RE: 3 Single Precast Box Culverts
RE: 3 Single Precast Box Culverts
With separate single cell box sections, there are no interior walls, only adjacent exterior walls.
Design of the top and bottom slabs will have to consider a minimum pressure condition on the sidewalls. This is why I mentioned/suggested grouting the gap between the sections; that way the adjacent walls push against each other, minimizing the moments on those walls. A granular material between the boxes could reduce the lateral pressure on those walls, creating a worse condition for the walls and the slabs.