Our sister site, Earthbag Structures.com, has lots of good information about building with earthbags in disaster prone areas. Click on the link to read the full article. This blog post is just a summary.
Earthbag is very strong in compression (carrying loads) but can benefit from additional reinforcing in key locations, including corners and next to openings, to resist lateral movement. Rebar and mesh can help earthbag walls resist wind loads and earthquake forces. With a thick plaster coating this can become a reinforced shell.
Rebar: When walls reach 1.5 m (60”) height, hammer a 1.5m (5′) long piece of rebar through the corner bags.
Bag: Always alternate bags at corners and stagger joints for strength. As high as possible on the finished wall, hammer a second rebar of the same length in. It will overlap the first. This is the simplest way to strengthen corners of earthbag buildings. [Ideally this rebar is tied into the concrete bond beam.]
Materials: Extra bags and barbed wire
Buttresses strengthen corners without rebar, and stiffen straight walls. Straight walls need a buttress or pier, intersecting interior wall, or a minor corner every 3- 3.5 m (10′- 11′). They also make it easier to add on earthbags to extend houses in the future.
Buttresses can be straight vertical, sloping, curved or stepped. Benches or wider wall bases will also strengthen straight walls if the bags are well woven (interlocked) into the wall. A vertical-edged buttress must stick out from the wall at least 60 cm (24”), and a sloping or stepped buttress 75 cm (30”).
Note: We have lots of articles on reinforcing earthbag structures against earthquakes and hurricanes. I plan to recap some of the most important reinforcing methods in the coming days and weeks, but in the meantime search our sites for complete information. Every website has a built-in search engine.