just run them down the invert of a ten foot diameter CMP. wow
I have seen a garden hose for a water supply run from a house on one side of the road going through a culvert cross drain to a trailer across the road.
Verizon does it all the time!
AND
You see why "wrinkled tin" aka CMP should NEVER be used as permanent crossdrain pipe. In this area 20 years is a long life.
Andy
same day, same project i found some expansion joint dug out from between an inlet slab and a concrete sidewalk. in its place was a cable. this is just really strange
AND
that's why were are mapping there. culvert analysis for a triple cell 10' dia CMP. twenty years old and all three are failing already
AND
About 25 years ago I spec'd CPP for driveway culverts on a small residential subdivision.
Municipal engineer, apparently needing something to comment on in his review of our otherwise perfect plan (no really!), insisted that we call for CMP, because he didn't trust CPP, as it was relatively new on the market.
Since we got paid as much for marchin' as we did for fightin', we let it go.
SS
AND
If a culvert is only lasting 20 years then the supplier and design engineer screwed up. The manufacturers that we deal with will warranty a metal culvert for 50 years or more if the engineering is done properly, and their representative is onsite during the installation.
AND
The problem in our area is the pH of the soils. Standard CMP will melt in 25 years. Galvanized pipe is good for 5-10 years longer than CMP. This is especially true in the areas where mining of lead and zinc took place.
AND
"Since we got paid as much for marchin' as we did for fightin', we let it go."
I've never heard that one before. I love it.
Live by it actually:-)
Don
AND
We have a similar problem; it's part of the design process for the engineer to check the PH of the water, the flow rate, and the expected level of abrasion from sand and gravel. All of that information goes to the supplier and they come back with recommendations for thickness of steel and coatings. The length of warranty available depends on which of the recommended options you pick.
Steve
I understand what you are saying but in the area where I practice I haven't seen any steel culvert that didn't corrode. We've tried bituminous coating (added a few years), aluminum coating (instead of zinc, again added a few years), bituminous coating with paved invert (added a "few" more years). The problem is that once the "coating" is penetrated the steel begins to corrode, the rust expands and cracks more coating, and soon the corrosion takes over. CMP is fine for certain locations but NOT in "permanent" crossdrains.
Andy
Steve
>CMP is fine for certain locations but NOT in "permanent" crossdrains.
>
> Andy
Again depends on the location.
We have CMP's that were installed in 1955 that are performing fine.
We are getting away from traditional large diameter CMP's and instead constructing bridges or culverts that incorporate spread footings and open channels.
This is for the holy fish.
> I have seen a garden hose for a water supply run from a house on one side of the road going through a culvert cross drain to a trailer across the road.
Encroachments in culverts (and bolted to bridges) is common, usually a minor utility or farmer type. We don't need no stinkin' permits!
