asphalt cracking 6

[Good_Guy]

All respected friends

A newly laid asphalted road has cracked longitudinally upto 10 m apprx so far. ( see attached photos)

There is no concavity observed

The road is inside an industrial facility with occasional medium sized trucks.

The subbase/ base / asphalt is about 10 months old.

Anyone has idea of the longitudinal asphalt crack?

Thanks

 

[oldestguy]

Seeing this is a side hill situation, I tend to believe the site grading for that road was not up to the usual highway requirements. Also, it may be that this crack is the junction between cut on the left and fill on the right. The fill may be slipping down hill. It may be due to the natural ground below or the fill itself as low shear strength. More info on the area, the weather conditions and specifications will help. As of now I suspect sub-standard earthwork.

 

[cvg]

is there a storm drain pipe running underneath that crack...

 

[Good_Guy]

CVG

Yes
There is a stormwater pipeline running adjacent and you can see a pit in the picture (along the kerb line. This work was aslo carried out by the same contractor

Thanks

 

[Good_Guy]

oldestguy
Very valuable information

Thanks a lot. Your analysis appears to be very close to what has happened

 

[Mad Mike]

My eyes differ slightly from OG's - straining to look at your photo, it appears the entire road prism has been cut- that seems to be a shotcrete retaining wall or similar structure on the right hand side.

If so, and noting the grassed infiltration strips on either side of the roadway, I'm going with water ingress...was subsoil drainage installed alongside your road?

All the best,
Mike

 

[oldestguy]

The main thing that I can relate this to, besides cut and fill situation is filling for a road over a deposit of sedimentary prat. In those cases the road fill splits and each side goes "its way", leaving a crack down the center.

 

[cvg]

I would lay dollars to donuts that the storm drain trench is settling, the pipe is leaking or both.

 

[oldestguy]

My bet is a poor job of placing and compacting (if at all) of the fill. Storm drain is likely near or under the curb line. There is no sign of settling that I can see. The green thing at the inlet might be a local settling however.

 

[Mad Mike]

I'm going with an inadequate clayey subgrade that is saturated from water infiltrating the grass strip on left of the photo, probably compounded by poor asphalt - let us know the outcome, seeing as bets have now been placed!

Mike

 

[msquared48]

Lots of excellent possibilities here.

Personally, I thinks it’s alligators.

Mike McCann, PE, SE (WA, HI)

 

[Good_Guy]

CVG
This possibility was considered very seriously. Thorough inspections has not revealed any trace of settlement of the drain pipe/ trench


Thank you

 

[Good_Guy]

oldestguy
No settlement of the drain pipe / trench

The green thing is just paint over some wrong signage that will be corrected soon

 

[Good_Guy]

msquared48
The owner has brought his on geotech / asphalt specialist
The contractor is also seeking outside opinion

Will wait and watch and keep posting

 

[Good_Guy]

Thanks to all for excellent responses

 

[oldestguy]

One thing we (I) missed is a cross section view of this road and the nearby ground up and down hill. Perhaps your specialists will make one up as part of the check.

 

[KutEng]

Have you considered that your roadway may be sitting directly between divergent tectonic plates and the only thing preventing an earthquake is your excellently placed asphalt?