×
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

LRFD Gravity Wall Design

LRFD Gravity Wall Design

LRFD Gravity Wall Design

(OP)
Has anyone started working with the LRFD code to do simple gravity wall designs?  In my work so far it appears that eccentricity checks and bearing capacity checks come out similar to previous design methodologies, but I am running into some issues with sliding.  Is anyone else finding it necessary to add foundation keys to stabilize their walls?   

RE: LRFD Gravity Wall Design

Yes, I've found that sliding is a huge issue with LRFD.  The deadload of the wall (which helps create friction) has a small load factor (like 0.9), but the horizontal earth presures have a pretty high load factor like 1.5.  It creates a "perfect storm".  I've had better luck with spreadfooting retaining walls than with pile supported retaining walls.  For pile supported retaining walls, it is simply very difficult to get enough reaction on the toe piles (presummably battered) for their horizontal component reaction to resist the horizontal forces.  I truely believe AASHTO has more work to do to re-calibrate the load factors.....probably won't happen in my lifetime....

RE: LRFD Gravity Wall Design

Here is the program to design wingwall using LRFD. Need MathCAD to run the app.
https://www.nysdot.gov/divisions/engineering/structures/design/design-analysis-programs

RE: LRFD Gravity Wall Design

Sliding will always be issue using LRFD. LRFD always require bigger section and this is the reason why contractors try to avoid LRFD specially during these times when they are realizing bigger sections on already bid jobs.

RE: LRFD Gravity Wall Design

FoS should be 1.0
 

RE: LRFD Gravity Wall Design

(OP)
VoyageofDiscovery:

I don't follow you.  

Are you saying that MIBridgeEng and I are using the wrong factors?

Please elaborate.

 

RE: LRFD Gravity Wall Design

I assumed you were accustomed to FoS = 1.5 for sliding with WSD.

Basically the resulting factored resistance should be at least equal to the factored base shear force.

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