Earthen buildings are strong in compression, but need help against tension or bending stresses. The barbed wire and vertical rebar in earthbag add important tensile strength.
More than 50 earthbag buildings in Nepal have recently survived 0.5- >0.7g of earthquake motion. This same motion destroyed poorly reinforced and unreinforced masonry buildings around them, mud block and brick alike.
But existing earthbag is not magic. Standard earthbag has its limits. Adobe reinforcements that have performed well in New Zealand’s >2 g seismic risk show us what earthbag needs.
Here are three new options for building stronger earthbag, including intermediate levels for Nepal’s 1g to 1.8 g risk areas.
Owen Geiger and Kelly Hart have been instrumental in developing these guidelines. We welcome more comments and help.
Type A is the standard earthbag method used in low risk zones. Because Nepal’s quake risks are for motion 1.5- 3 times as severe as that experienced in the recent quakes, we encourage builders in Nepal to consider adding some improvements to earthbag, like Type B or better.
Read the complete report Earthbag Options for Nepal online at http://buildsimple.org/resources/EB%20Options%20for%20Nepal.pdf
And see BSI’s simple visual building guides like Building EB Walls Better- we will be updating them soon, but can be found at http://www.buildsimple.org/earthbag.php – follow the link on upper left.
Special thanks to Patti Stouter at Build Simple.org for her remarkable efort making this report available. She must have squeezed in 100 or more extra hours into her schedule to pull this report together in such a timely manner.
I was just wondering if there might be a way to use PVC rebar to fortify the walls or does it have to be steel?
Thank you,
-Sarah
Someone suggested this last week. PVC is not meant for structural purposes. There is some strength that’s adequate for things like hoop houses (arched greenhouses), but it’s not strong enough for houses. Rebar would be far stronger.
i am glad that earthquake resistant earth bag building seems most effective in country-side of Nepal and the most important things is that the people who are specially living in rural area they also can afford to build such as Mud block houses with affordable cost.
Thanks
This was very informative and needed.
Wow, I really like it. Looks very simple and useful.
I am interested in all topics. I am from Austria (private Person) and now in Nepal as freelancer and Little Part of a Family who is affected by Earthquakes (one member and friend died). We realized a small Project in solokhumbu …healthpost in changha which is not really affected by Earthquakes. I have Limited Time here. I can stay here until 30th of June. Thank you!
Hi Owen, do you still recommend the French drain foundation system for Nepal or will you advise something else. I wander to Know if you want to stick on this system or not? Don’t you think the structure may jump on the Foundation? Just wandering, thank you
Best regards
Laurent
Yes, unless there’s no frost and almost no rain or snow.