Need to calculate the I beam size for an underground construction. the
building is (inside dementions 60 feet X 100 feet. The walls are
reinforced concrete 24' wide, the colum for I beam support is 18" on
each end. There will be a reinforced concrete roof (which this beam
will support) of 18". There will be 12 inches of pea gravel (for
drainage) and 36 inches of soil on top of the structure. I have
assumed a soil moisture rate at 1 cu ft of water (68# sq ft) pea
gravel at 112 # sq Ft soil at 93# sq ft. I do not know how to
calculate the wieght of a d8 dozzer to push the soil over the
structure, do I calc the full amount of the dozer divided by the foot
print of tracks ????
What size of I beam would be needed for a 4 ft spacing on center?

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Request for Question Clarification by redhoss-ga on 23 Sep 2006 06:08 PDT

I didn't mean to discourage you. I was just trying to make things
easier. If you want, I can answer your question as stated.

What about using temporary construction support so you don't have to
consider the dozer weight.

Can't you use a Bobcat?

Don - It sounds you are preparing a bunker for nuclear war. You should
watch the movie "Blast from the Past" for ideas. Back to your point:
If you are considering a construction project of this magnitude
slapped together without the assistance of a structural engineer and a
qualified contractor, you are exposing yourself to enormous risk of
collapse. For starters, support columns on 20 foot centers (permanent,
not temporary) would go a long way toward a more practical, safe, and
cost effective design.  You didn't specify if money is no object. 60
foot clear spans would not be an I-beam exactly. It would have to be a
fabricated truss.  Here is a primer in bridge and truss design to give
you a sense of the complexity of your project:

http://pghbridges.com/basics.htm

This could easily get mighty expensive, hence the advantage of
additional interior supports, which would allow the use of simple
beams. Please take my advice - This is definitely not a job for a
beginner.  Good luck!  Big Blue