Saturday, January 30, 2010

Earthquake resistant buildings for Haiti

diagram non-copyright R.Lawson

After the earthquake in Haiti I looked at earthquake predictions, then at earthquake engineering - making buildings more earthquake resistant. It is impossible to make a building earthquake-proof, but we can decrease the likelihood that it will crush the occupants. Buildings in seismic zones should be made to seismic specifications, but it is possible to retrofit existing buildings in an affordable way.

It's not rocket science, its triangulation.

In the above, diagram (a) above shows a conventional modern concrete building, with the floors hung from a few vertical concrete pillars. When the earthquake (e) shakes the ground, the pillars crack at (d), and the whole building collapses, concertina style. The structure is supposed to be stabilised by the walls, but they shake out with the tremors.

The solution is to triangulate the corners with robust concrete or wooden beams, as in (c). This is not difficult or expensive, and this triangulation should be included in the Haiti reconstruction. Interestingly, traditional timber framed buildings are earthquake resistant. It is good to use timber, so long as it is replaced, as all timber contains an equivalent mass of CO2 taken out of the atmosphere.

I have a feeling that the main block to earthquake resistance and engineering is denial.


Simon said...

Given the abundance of lime over there I would suggest Eco Domes whcih are earthquake resistant. They are relatively cheap as well

DocRichard said...

Hi Simon
There is an active Permaculture discussion group that is talking about housing, both emergency and longer term.

Simon said...

Thanks, nice to see if all their depts werer cancelled. And getting France to pay back the 20 Billion in reparations would be the proper thing to do.

Anonymous said...


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Well it's a little late for this, I afraid that more earthquakes are going to happen in this apocalyptic time, everyone should be careful.