×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

pseudo-static coefficient

pseudo-static coefficient

pseudo-static coefficient

(OP)
Hi all,
According to WSDOT Getechincal Design Manual(6.5.3.1), horizontal pseudo-static coefficient Kh=0.5*PGA, the PGA at Everett, WA is 0.3, so I think Kh is 0.5*0.3=0.15.

But I read some getechnical reports, Kh=0.5*0.3*1.18=0.177 was used in these reports.  what does 1.18 mean?

Thanks

RE: pseudo-static coefficient

wshi,

Suggest you contact the author of the reports containing the 1.18 factor...

Jeff

Jeffrey T. Donville, PE
TTL Associates, Inc.
www.ttlassoc.com

The views or opinions expressed by me are my own and do not necessarily reflect the views or opinions of my employer.

RE: pseudo-static coefficient


Probably it's the soil amplification factor, variable according to stratigraphic sequence:

the formula would go: Kh = Ag/g * S for foundations, and
Kh = 0.5 Ag/g * S for retaining walls, S stands for Soil (amplification).

I'm answering based upon european EC8 guidelines, but I saw in IBC and NEHRP the rationale is the same.

RE: pseudo-static coefficient

wshi,

The 1.18 is the soil amplification factor.  It is used to take the peak bedrock acceleration (PBA) to peak ground acceleration (PGA) and is used to account for site soil amplification.  The PBA in Everett is 0.3.  The PGA is 0.354.

PS.  I am part of the I-5 Everett HOV project D/B team.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources