Seismic Underground? 2

[Zulak]

I'm designing a two-level parking garage to be below grade (with approximately 3 feet of soil over the top. Since the structure is buried (i.e., part of the ground), are any seismic loads really generated?
I would appreciate any thoughts.

Zulak

 

[pphuddar]

As u mentioned the case, I think u will need to consider
earthquake force.The height of structure above ground
determines the earthquake response of framed structures.
However please look at retaining wall analysis for
earthquake.
If u decribe your case more in detail i would be able
to tell u more about this

email address : pphuddar@yahoomail.com

Prashant

 

[Qshake]

I would be concerned of displacement based concerns over force based ideas. Perhaps look at rectangular tunnelling in high seismic areas. check out the database at MCEER, EERI and NICEE.

 

[zaher]

in fact,if the under structure is under ground, and basement is braced with retaining walls, you can consider that the basements are stiff enough that the fixity level of structure is on the ground level, so no base shear distribution on the under grade slabs, or seismic effect, on condition that basement is braced as mentioned before.

zaher_yahya@engineer.com