Water came up while doing excavation work for a road

[haowangeng]

we found water while doing excavation work for the road's subgrade.
The water seems running through sand and smaller rocks as we found them.

the contractor suggests to pump out the water and remove all the saturated materials and put 2-3' of clay at once.
I think that might create a weak lift and might have negative impact on the road in the future. (Winter here is 40 blow)

Any suggestions?

Thanks.

 

[shobroco]

Install drainage & find a place for it to go to or you'll never stop fixing that road. You have to remove the water, you can't push it back.

 

[concretemasonry]

Combining clay with a large amount of water is not good in the long term, but ti does keep a job going for a while. The saturated material that is "suggested" to be removed is probably better that the readily available clay. - Where is the water going to move to?

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[haowangeng]

Thanks guys.
I think what we will do is that leave it over night...if it is underground water, we will lower the watertable 2-3', and re-work the subgrade as usual.

If the water come up the next, which means it is actually a spring....i guess we will have to install some sort of drainage, and re-direct it.

Any other suggestions?

 

[msquared48]

Change the road alignment?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[cvg]

My suggestion would be to hire a geotechnical engineer

 

[Drumchaser]

Place underdrain system: perf. pipe laterals on a 45 deg angle across roadway (50' spa) tieing to non-perf trunkline which is the outfall into front slope or drainage structure. Have also seen underdrain systems placed along outside (under) curb line.
There are a few limitations...the most important being good fall to an outfall location.......the water has to have a place to go.
They work great, and have been used in this area for decades.

Trench is bedded w/aggr., perf pipe (encompassed in filter fabric) placed, more aggr. placed around perf pipe, then the last foot or so is backfilled with subgrade material.

 

[fattdad]

filter frabric, 12 inches of open-graded aggregate (include some perf pipes to facilitate gravity discharge), filter fabric and then properly compacted backfill. Not sure I'd want to use clay though. . .

f-d



¡papá gordo ain’t no madre flaca!

 

[cvg]

if this is a spring, you might need a dewatering permit