Cob/Earthbags/structural issues

[Otherfish at aol.com]

to duckchow & all
you wrote
<<	I agree that monolithic cob is stronger, but I'd rather stand for long
periods in a dome made of earthbags than a dome made of traditional cob,>>

I did'nt mean to imply using cob for a dome structure - in fact, the idea of
putting  a heavy mass of earth overhead makes me uncomfortable  - again, the
appropriate use of materials - make the roof as light as you can & it won't
present a danger !!
-I don't mean to be narrow minded about this & feel it will be great if
someone who is so inclined can perfect tenhniques for building weatherproof
roof structures mainly with earth
-we all benefit from the gifts of the adventerious

earthbags seem way beyond cob for this use - just shield those plastic bags
from the ol' UV

Re earthbag foundations:
I stated:
>altho I'm not sure it ...(earthbags)... is such a good idea
>in seismically active locations

you replied:
	>>A concern I share. But perhaps I haven't quite grasped all the nuances of
Khalili's work. (OK, it's likely that I haven't. OK, almost a certainty.
OK, I definitely haven't.)<<

The structure's at CalEarth (Khalili's) appear to me to be basically
compression structures & the principals are well explaind in his book ( worth
reading ) 
- I don't know how the foundations of these work

I was refering to the concept of building an earthen building on a continuous
foundation in areas subject to seismic activity - that is to say some sort of
a foundation that has ridgidity and can act in tension - as I understand it,
earthquakes can subject a building to both horizontal and vertical forces &
these will act to take a building apart in  both these directions  if not
countered in some way - the "demon" reinforced concrete is in fact real good
at this & is a valid choice (earthquakes are part of the NATURAL complex of
forces with which we must deal & ought not to be ignored)
-my feeling on the face of it is that earthbags do not have the requisite
ridgidity to do this - perhaps I'm wrong about this & will be pleased if that
turns out to be the case - once again tho, prudence seems justified when
dealing with the issue of possibly creating a dangerious building - hope
someone can shed more light on this either in pointing to established reliable
data that shows earthbags can create a safe seismic foundation or by doing the
testing to make the case !! 

regards
john fordice
otherfish at aol.com