From the Asia Challenge design brief:
Design Considerations: Participants are challenged to incorporate the needs of the community and to employ sustainable and/or local building material using local labor to realize their design. Designers should also take into account the remote nature of the site and costs associated with transporting materials in developing their designs.
The use of local materials pretty much dictates some form of mud (green or fired, bricks or bulk) as the primary building material. Since firing bricks has significant economic and ecological costs, unfired mud (adobe) is the most common choice of construction material in under-developed areas. The material itself is essentially free, and the cost of the labor all goes into the local economy. Also, the thick walls used in adobe construction have a very high thermal mass, resulting in excellent thermal insulation.
But adobe by itself is prone to collapse in an earthquake. Since Nepal is seismically very active, we have to take that into consideration. For reinforcing, bamboo is common throughout Nepal and lumber is available, if more expensive. Manufactured materials, such as concrete, steel and nylon, can also be used, but are less desirable if there is a suitable local alternative.
There are many Internet-accessible resources on building earthquake-resilient structures with adobe. Here are some that seem most applicable to this project.
Tutorial on designing and building structures with adobe bricks
http://www.world-housing.net/uploads/WHETutorial_Adobe_English.pdf (English) and
http://www.world-housing.net/uploads/WHETutorial_Adobe_Spanish.pdf (Spanish)
Here are some specific design recommendations from the above.
- The wall height should not exceed eight times the wall thickness at its base, and in any case should not be greater than 3.5 m.
- The unsupported length of a wall between cross walls should not exceed 10 times the wall thickness, with a maximum of 7 m.
- Wall openings should not exceed one-third of the total wall length.
- No opening should be wider than 1.2 m.
- Provide piers of at least 1.2 m width between openings.
Compressed Stabilized Earth Blocks (CSEB)
This is a technique developed by the Auroville Earth Institute and has been approved by the governments of India and Iran for use in earthquake resistant shelters.
They require a manually operated press and the adobe bricks are 5% concrete to aid in their anti-shearing and waterproofing. (I am currently seeking ways to substitute the cement for a locally available material)
CSEB
http://www.earth-auroville.com/?nav=menu&pg=technologies&id1=9
Auram Press
http://www.earth-auroville.com/?nav=menu&pg=auram&id1=3
