Earth Sheltered Roof Structure Unofficial Poll

[4qualityengineer]

What type of structural system is preferred these days for earth sheltered roofs? The project I am working on is in a mountainous rural area, will have about 2' plus or minus of earth on the roof, and will be constructed into a rocky hillside. I am thinking either a steel deck/joist/beam system or precast panels would be most cost-effective. The retained side will be concrete and we are looking at using CMU for the non-retaining sides. Thanks in advance!

 

[msquared48]

If it's a very remote site, I did an earth structure on Henry Island in the San Juans years ago - small spans though - 12 feet or so.

It was a thin concrete shell (3" or so) that was heavily reinforced with chicken wire that also served as a form grid to hold the concrete matrix while it cured - the same technology and forming techniques as for concrete vessels. Worked great and cattle could eat the grass from the top. Blended into the hillside real well too.

Additionally, the concrete was mixed on site and all the materials were easily transportable by small boat and hand to the site.

Mike McCann
MMC Engineering

 

[4qualityengineer]

Mike,

I would like to have seen your calcs for this. : ) Not that remote, just has a long, curvy driveway, so am not sure that precast is the best option for this. I am looking at some longer spans - 25-50' if we can get it.


Cody Geisendorfer, PE

http://www.quality-engineering.biz

 

[idecharlotte]

I'm not sure of the geometry of the structure but I would consider post-tensioned P.I.P. concrete roof slab for those spans. That way, you just have to drive concrete trucks up and not deal with hauling long steel members or using a crane.

http://www.idecharlotte.com

 

[a2mfk]

Anyone make sure a concrete pump truck can get close enough? If so, CIP may be a good solution, since formwork and rebar is a lot easier to get up and into a tight spot than hauling CMU or other materials...

And talk to a water/moisture membrane expert!