IBC / ASCE Seismic Load Effect "E" Question
IBC / ASCE Seismic Load Effect "E" Question
(OP)
Understanding that the intention to combine the "horizontal" and "vertical" effects in the formulas ( E = pQe + .2SdsD) in each reference to attain the seismic "E" value to use in the load combinations, is it not redundant adding the .2Sdsx(D) back in when the Qe is the horizontal value, assumed to equal V, which based on the Dead Load in the first place?






RE: IBC / ASCE Seismic Load Effect "E" Question
RE: IBC / ASCE Seismic Load Effect "E" Question
The first term is the HORIZONTAL.
So they are not redundant in that they are forces applied in different directions at the same time and in the same load combination.
RE: IBC / ASCE Seismic Load Effect "E" Question
RE: IBC / ASCE Seismic Load Effect "E" Question
RE: IBC / ASCE Seismic Load Effect "E" Question
It seemed like it could be a perpetual spiral...adding more dead load could add more lateral load being based on the dead load and so on.
Reading too far into it perhaps. Should be taken exactly as the formula is written.
Thanks.
RE: IBC / ASCE Seismic Load Effect "E" Question
That horizontal load is derived completely separate from the vertical seismic load.
They are then combined in the load combination. I guess I don't see how they could perpetually spiral.
One way to think about the combinations is not as an "formula" as you put it - but rather as a sum of effects on the structure.