protecting a concrete pipe

huangyhg

protecting a concrete pipe
i have a road/bridge project that i am working on where we have a 36" diameter concrete pipe that was covered with 6.5' of fill.  after the project is done, the pipe will be ocvered with 24' of fill in some spots.  the pipe can't handle that amount of fill, so we will need to protect the pipe in some way.
the thought i had was to build a cast-in-place concrete "saddle" (imagine a channel shape) that spans over the pipe and carries the load from the soil above.  the legs of the channel will have load on them due to carrying the weight of the soil above.  at first i thought bearing pressure under those legs would be an issue, but the more i think about it, the more i think that allowable bearing pressure isn't an issue, but settlement might be.  does that sound right?  is settlement what i have to worry about?
any other thoughts? (our geotechnical engineer for this project is out until next week, so he hasn't responded to my email yet)

well, the settlement will be a function of the bearing pressure, but yes you should worry about it, because if it settles it could end up loading the pipe it is meant to protect in a manner that is worse than the unprotected condition would have been.