Contact US

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!

*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

Do you use the new seismic screen analysis for slope stability yet?

Do you use the new seismic screen analysis for slope stability yet?

Do you use the new seismic screen analysis for slope stability yet?

DMG Special Publication 117 and the Recommended Procedure for Implementation of DMG Special Publication 117, recommends using a seismic screen analysis for determination of the seismic coefficent for slope stability analyses. We have found that the screen procedure yields seismic coefficents on the order of 0.5 to 0.7 of the peak ground acceleration. (Santa Cruz County is located to several major faults and has experienced severe ground shaking in the recent past, most notably the 7.1M 1989 Loma Prieta Earthquake). Some of our peers, with both geotechnical and geologic backgrounds, continue to use a maximum seismic coefficient of 0.15g, which is based on Seed's research.

The Geotechnical Engineers of Santa Cruz County would like to determine what other people are using and what really is the current state-of-practice in our area. So....how do you determine the seismic coefficient for seismic slope stability analyses?

R. Dees
G.E. 2623
Santa Cruz, California

RE: Do you use the new seismic screen analysis for slope stability yet?

While I'm a licensed C.E. in California, I haven't practiced there in over a decade, so I'm a little rusty on the current earthquake stuff.  Your question gives me an excuse to get boned up again -

If you intend to argue against the use of the CGS (formerly DMG) SP 117 "seismic screen analysis technique" (see http://gmw.consrv.ca.gov/shmp/SHMPsp117.asp ), then you'll need a lot more than some (generally anonymous) on-line opinions on the subject.  First, you will need to be able to cite specific examples where the procedure produces erroneous results.  Then you'll have to show that Seed's work is still the best approach.  And that will take a lot more than, "this is how we all do it around here."

Don't get me wrong - I'm not saying that the "seismic screen analysis technique" is better than Seed's recommendation.  I'm simply reflecting on what it will take to effect a change in CGS's recommendations...when dealing with one of the local governmental agencies.

As a side note: I couldn't find a reference to a "seismic screen analysis technique" on the cited web site.  And when I read (ahem, skimmed) the Special Publication, I didn't see anything particularly troublesome...

Please enlighten us with specific references, preferably on-line resources.  We're happy to act as a sounding board for you -

Please see FAQ731-376  by VPL for tips on how to make the best use of Eng-Tips Fora.

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! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close