The idea presented here is for Haiti and other areas susceptible to earthquakes. It’s a very simple concept, but even small steps like this one can save lives.
The main idea involves reinforcing corners of earthbag buildings with plastic mesh or plastic fencing. For background information, see my previous post on Low Cost Reinforcement of Earthbag Houses in Seismic Areas that discussed the research at the Catholic University of Peru. Blondet, one of the lead researchers on the project, said plastic reinforcement mesh was the strongest method they’ve tested in 35 years of seismic research.
The main addition here is ¼” rebar to secure the plastic mesh. Add ¼” rebar and plastic mesh on both sides of the wall and tie together through the wall with baling twine or nylon cord. Bend the rebar and plastic mesh at the top of the wall and embed in the reinforced concrete bond beam. Embed it in the concrete foundation if you have one. Lower cost chicken wire or fishing net may be adequate for the remainder of the walls. There’s also a 1/2″ internal rebar pin pounded through corner bags. Note: earthbag walls in non-seismic areas typically do not use mesh unless required by code.
what is it
This shows an additional reinforcement concept to make earthbag buildings more secure in seismic events.
Owen, do you think any structure built in a seismic zone needs this type of reinforcement, or could a smaller dwelling get away without it. I see the importance of developing some “standards” for people to follow.
Do you think a round structure could benefit from extra rebar and mesh, or does the shape alone keep the structure sound?
Nabil Taha, the engineer who’s agreed to stamp earthbag plans in seismic and non-seismic areas, has written detailed specifications. It should be finished soon and then I’ll write a blog post about this.
I recommend this mesh reinforcement method for most rectilinear buildings in seismic areas. Tiny shelters 10’x10′ interior or less should be fine with regular plaster mesh on both sides tied together through the wall. Add vertical rebar pins through the bags at corners and on each side of door and window openings.
It’s very difficult writing general earthbag standards, because there are so many variables: seismic zone, shape and size of building, construction details used, roof design, etc. Almost every building is different. Plus, we have limited feedback on which to make design decisions.
Round structures are definitely more stable, but in seismic areas I would add plaster mesh on both sides and the vertical rebar pins described above. Better safe than sorry.