Home
Contact
Privacy
Resources

MORE INFO

Cost and Prices

THE HOMES

Adobe
Bamboo
Burdei
Cave
Cast Earth
Ceramic
Clay
Cliff
Cobb
Compressed Earth Block
Earthbag
Earth Berm
Earth Home Advantages & Disadvantages
Earth Home Plans and Designs
Earth Sheltered
Earthship
Fogous
Grass
History of Sod Houses
Icelandic Turf
Lodges
Mud Brick
Pit
Pueblos
Poured Earth
Quiggly Holes
Rammed Earth
Rice-Hull Bagwall
Sandbag
Souterrains
Stone
Straw Bale
Superadobes

Underground

Underground Domes
Underground Home Plans and Designs
Wattle and Daub

 

Superadobes

Almost a third of the world's population lives in dwellings made from earth. As we become more concerned with our use of natural resources, this is expected to increase. Advances in technology now make it possible to very effectively build using superadobe construction (the super-duper version of regular adobe houses).


Superadobe

The materials for a superadobe wall are simple - just barbed wire and sandbags filled with earth. For eons, sandbags have been the chosen materials for building dikes, and have also been used for protection in war zones. Once these temporary structures served their purpose, the sandbags were emptied and disposed of. Today, superadobe (or superblock) construction is used for permanent construction.

In the past, the main problem using sandbags for construction has been that they lack tensile capability, which means that the structures being built had to be low. It was also impossible to create domes or arches. With superadobe construction, barbed wire is placed between the layers of sandbags in order to create tensile resistance. Shear stresses are transferred from one sandbag to the next. Bigger sandbags can be used, so walls can be made higher. It is also possible to create vaults, arches and domes.

Superadobe sandbags are tubes made of fabric. They are filled with different types of particulate, fluent material, which may include earthen, organic sand along with manufactured or recycled materials that then become self-supporting, forming into a block. The bags themselves are coated with protective materials, meaning that durable exteriors do not need to be shielded.


Because of the flexibility of the sandbag, monolithic structures can be built in curved forms, completely from earth. Most traditional roofing systems can be eliminated.

Single-curvature and double-curvature compression shells don't transfer stresses from element to element. Instead, stresses are transferred along the structure's surface. With beam and column construction, when a single element becomes overloaded to the point of failure, adjacent elements are affected, and they all fail. This frequently results in the collapse of the entire structure. With a domed structure, excessive loads are shed with localized failure and the remainder of the structure remains intact.

Live-load and dead-load stresses transfer to the ground, spreading evenly along the dome or bearing wall's perimeter. With beam and column structures, the loads get transferred by way of a footing underneath each column. This results in severe stresses to the upper structure that can cause cracking, particularly when there has been frost-heave. This is why most foundations go below the frost line. In a monolithic structure, frost-heave and differential stressing don't present these problems. The structural load is distributed over a larger area, so "soft spots" in the soil have negligible effect.

One of the greatest challenges in modern construction is creating structures that will withstand natural disasters like earthquakes. As our climate changes, this will continue to be of concern. The basic shape of most structures creates problems, since the weight of the structure is not evenly distributed between roof and foundation.


Frequently, there is a good deal more weight on the upper floors, and deep foundations and footings can come apart at the structure's base. There are designs that can provide shifting capabilities, but they are often cost-prohibitive. A vaulted or domed structure can be expected to be much more stable in the event of an earthquake. The continuous foundation can actually slide across the ground as it moves, while the upper structure resists damage.

Conclusion

Superadobe, using hand-filled or pump-filled sandbags combined with four-point barbed wire, is a highly effective construction method. It is eco-friendly, and lends itself very well to structures that can be designed to withstand even earthquakes.


 
© 2015 EarthHomesNow.com. All Rights Reserved.