Earthen embankment over existing ground with trenched in watermain
Earthen embankment over existing ground with trenched in watermain
(OP)
Hello all,
I am an intern at a municipality and I am having trouble finding a solution to a problem my boss posed to me. The WISDOT is placing a 20 foot fill over our DR-18 S-900 water main pipe that is trenched in 6.5 feet below existing ground. All in all there will be 26.5 feet of cover over the pipe. We are trying to find out if this will cause too much stress on the pipe and if it should therefore be replaced with cased pipe. Thank you for any help.
I am an intern at a municipality and I am having trouble finding a solution to a problem my boss posed to me. The WISDOT is placing a 20 foot fill over our DR-18 S-900 water main pipe that is trenched in 6.5 feet below existing ground. All in all there will be 26.5 feet of cover over the pipe. We are trying to find out if this will cause too much stress on the pipe and if it should therefore be replaced with cased pipe. Thank you for any help.





RE: Earthen embankment over existing ground with trenched in watermain
RE: Earthen embankment over existing ground with trenched in watermain
RE: Earthen embankment over existing ground with trenched in watermain
RE: Earthen embankment over existing ground with trenched in watermain
What is the length of pipe that will be under the fill?
RE: Earthen embankment over existing ground with trenched in watermain
You should look it up, possibly on Google. Or see if you can find the test book from Spangler (who is long dead). There are several papers on the subject that I came u with with a Google search, including some design guidelines.
What it basically involved is excavating down some with a trench over the pipe. Fill it with compressible stuff, like corn stalks.
Then, since your fill goes above that, build a reinforced concrete slab over the Imperfect trench and for some distance on the sides, say 10 ft. each way.
then place your fill.
I suggest seeing if Interstate I-94 original plans show the work done at EauClaire. Done about 1960. After all it is still WisDOT.
A similar thing was done at Madison for an active MMSD WWForce main next to the Yahara River, under pressure, that had to be built over by a bank with footings bearing over it. They covered the trench area with a reinforced slab and went on with the work, but did not do the Imperfect Trench.
You make the ground alongside the trench carry the load.
I betcha none of the above commentators heard of it before. Once in a while it comes in handy.
RE: Earthen embankment over existing ground with trenched in watermain