Earthquake design
Earthquake design
(OP)
when designing a structure for earthquake, would the earthquake forces be higher at the top of the structure or at the base? or would the earthquake loads be dependent of the dead loads on the specific floor? thanks





RE: Earthquake design
RE: Earthquake design
Nigel
RE: Earthquake design
THE SEISMIC FORCES WILL BE HIGHER IN THE TOP STORIES!!
NIGEL
RE: Earthquake design
When we look at the story shear that is influenced only by two items mass and acceleration. Atop a building, with smaller members as building design practice dictates, the displacements are larger as are the accelerations owing to the less stiff arrangment. Less mass more acceleration. Near the bottom, more mass, less acceleration.
But because load path is important and the forces are transmitted to the foundation the ultimate seismic forces at the bottom of a structure are larger.
RE: Earthquake design
RE: Earthquake design
RE: Earthquake design
RE: Earthquake design
Now I cannot find that article. I thought I had saved it, but if so it is so well saved it cannot be uncovered. Has anyone else seen that article and if so where in the world is it??
Thanks
RevanK
RE: Earthquake design
Check out this site for earthquake design. http://www.bssconline.org/
What you may be remembering is that the USGS has published maps of probabilities of lateral accelerations. FEMA has incorporated this information into their design reccommendations, and it also shows up in the Army Corp site, and the ATC-49-1 report:
http://www.atcouncil.org/
The end result is that bridges with piles in soft silt and clay will be designed differently than bridges on rock, even though they may be in the same seismic zone.