Seismic Parameters 2

[Kuhuh]

What the heck do the variables Ss,S1,Fa,Fv,Sms,Sm1,Sds,Sd,I stand for and how do they individually effect the design. I was told to look up the variables by the USGS ground motion parameter Java app. I'm not doing any designing but I need to obviously learn this and I did not take seismic design at school due to focusing on hydraulics only taught us horizontal force and vertical on dams but really limited. If you can refer a pdf or power point or just simply answer my question I'd appreciate it

 

[HSIII]

I would try deleting this post and reposting it in the strtuctural engineering other technical topics forum. You'd have a better chance of an accurate answer there.

 

[OldPaperMaker]

All of the variables that you noted are defined in Chapter 11 of a book called ASCE 7-05. The title of this book is "Minimum Design Loads for Buildings and Other Structures".

This book is referred to in the International Building Code which is what most building departments in the US use as their code documents. The book cost about $100 for non ASCE members.

 

[msucog]

do a search here on eng-tips. i've posted several very good reference links that explains it. essentially, IBC (via USGS data) has tried to encompass seismic accelerations that most readily impact 2 story and 10 story buildings (since most structures are covered by this range). the Ss corresponds to a 0.2sec spectral response and the S1 responds to a 1.0sec response...essentially you consider 1 story per 0.1sec. Ss and S1 correspond to bedrock accelerations and Fa and Fv take in to account how the motion is amplified by the soil above the bedrock. soooo, long story short, the Sds and Sd1 likely impact short and tall buildings more, respectively...but this is not always true.

try the fema site for education reports. fema 451 and 451b are good. search my comments here and you can find a full list of references i've suggested. you might also check out the latest reference CE book by Day.