Concrete construction

[Walter349]

I am working for a company who is installing cabins, which are ISO shipping containers in general description. The problem is, that the original plan was to install them onto reinforced concrete rafts. However, citing cost constraints, the program manager has changed this and substituted four un-reinforced concrete blocks, one at each corner.
The blocks are made by local contractors using un-supervised labour and local materials, (lets call this the Middle East)
The geographical location has serious seismic events and is a major risk. The blocks are not footed into the ground at all, just placed into position, the container is not secured to the blocks in any way.
So am I seeing problems where none exists? with using four un-reinforced concrete blocks of questionable quality to sit six tons of container on, in a seismicaly active area. Oh! people will be working in these, not to mention that the containers have vital, sensitive equipment in them, the failure of which will have serious ramifications.

Any thoughts on this ?

 

[msucog]

i picture your description sort of like a trailor park setup as far as container support. i would expect a trailor park to experience serious damage during a light to moderate seismic event since the thing will simply fall off the "foundation". for example, under normal circumstances, i don't see a lot of news about trailers falling off the masonry blocks and killing someone...they probably just get out of level over some period of time. this scenario might be different during a M7-8 earthquake. if the things are only one container tall and essentially level with the surrounding firm ground, at least the thing might just slide around on the ground surface (which could actually cause less shaking to the "stuff" inside versus one that is founded in the ground). the possibility exists that the thing could fall off its blocks if it is elevated or it could turn over if the surrounding ground surface is soft/loose enough that the edge of the container happens to dig in during the shaking/sliding. as far as the sensitive equipment inside, i suppose it's very possible that the shaking could damage the equipment regardless of how the container is founded (again, i suspect there'd be less overall shaking if the container is free to slide around--as long as it doesn't fall over). i suppose there's other ways to deal with the shaking but you'd probably not have access to those kinds of system due to your location---plus, i'd cross the line of pulling an answer out of my arse if i tried to ellaborate on damping systems for shipping containers.
i suppose someone (program manager, client, military, whoever) should evaluate what kind of performance/life expectancy they're expecting versus the cost of building the thing as well as the consequences of critical equipment failure (which could result anyway during a seismic event depending on the ruggedness of that sensitive equipment).

good luck!

 

[dicksewerrat]

Use at least four blocks at each corner. tie them together and let the containers move during the earthquake. Put some slack in the power supply. This is assuming that the project manager has the authority to make a change.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com