Sandy Site/Pervious Pavements 5

[cieg22]

I'm working on a parking lot for a flat site in the northeast that is mostly sand, with a very high water table. Drainage/retention is a huge challenge, and I was thinking about doing a pervious pavement. Bad idea?

Also, can anyone suggest a good read on the pitfalls of building on this type of site? Obviously our geotech will be providing guidance on all of this ultimately, but I wanted to get a head start.

Thanks.

 

[cvg]

start by doing some research on this site - see the google search below which shows that this topic has been discussed quite a bit before.

http://www.eng-tips.com/search.cfm?q=pervious pavement&action=search

 

[Ron]

I don't particularly like pervious concrete in freeze-thaw prone areas. Yes, it can be done, but all the stars have to align for it to be durable.

 

[jgailla]

I would not rely on pervious pavement to solve a drainage problem.
It can be used for environmental credits, but I would run an analysis to see what would happen to the drainage if it was clogged and acted as normal pavement.
Pervious concrete clearly works in drainage when unclogged for parking lots and drives that are not used constantly. It seems to clog in 2 to 5 years and I wouldn't want to rely on future maintenance.
In high traffic areas, the aggregate ravels. I haven't seen a good use for pervious asphalt pavement. It clogs much faster than the concrete and ravels much faster.
If your problem is drainage, I don't believe pervious pavement is the solution.

 

[bimr]

Porous pavement should be located at least 2 to 5 feet above the seasonally high groundwater table.

http://www.advancedpavement.com/index.htm

http://www.stormwatercenter.net/Ass...ces/Infiltration Practice/Porous Pavement.htm

 

[beej67]

I've seen some guidelines on using it in Maryland, which does freeze sometimes.

Design methods to avoid clog prevention:

1) Do your travel lane of your parking lot in regular pavement, and do the parking spaces themselves with pervious.

2) Include a header curb in your design, and wheel stops, and a 1 foot wide strip between the edge of the pervious pavement / wheel stops and the header curb that's just rounded river stone set on your base course. If the pavement clogs, the runoff still infiltrates the base course along this strip.

3) Also put in a drop inlet "just in case."

4) Lay in a perforated underdrain system below the pervious pavement base course, which ties into the drop inlet, in case the water table gets so high that there's nowhere for the base course to drain.

5) Ample use of permeable geotextile fabric at the base course / subgrade interface to prevent migration.

6) Specify a maintenance plan that includes routine cleaning of the pervious pavement areas, and also keeps the future owner from paving over the whole thing.

Also consider those StormTech chamber systems as an alternate. You might be able to get the same sort of net effect without having to worry about the surface clogging.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com