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

FE Strength Reduction Method for a Slope already have LEM FoS < 1

FE Strength Reduction Method for a Slope already have LEM FoS < 1

FE Strength Reduction Method for a Slope already have LEM FoS < 1

I am analyzing a slope in GeoStudio in Finite element method. Strength Reduction method. When I analyze with Limit Equilibrium method, I get FoS 0.7.

According to SRM method, the material strength should be reduced until we get non-convergence or huge deformation. In this case, how can I reduce strength as FoS is already less than 1?

Embankments are built stage by stage. 3 stages here. What method I select for stress analysis?
Replies continue below

Recommended for you

RE: FE Strength Reduction Method for a Slope already have LEM FoS < 1

Aside from the type of analysis - since you showed the slope strata, etc., it would be nice if you included the soil types and strength/density for each of the strata and location of groundwater table. You say that you are building in stages . . . then the base layer (yellow) I suppose would be soft clay. With the first stage going on, how long before the second stage? During that time the lower clay layer will see an increase in strength due to the consolidation due to the first stage (and subsequently to the later stages). Are you taking this into account with the succeeding stages in your LEM? We built RE retwalls on 6 m of very soft clay in stages (with wick drains to speed up consolidatin) successfully taking into account the increase in the soft clay's increase in strength - 11 m high wall settled 1100 mm during construction.

RE: FE Strength Reduction Method for a Slope already have LEM FoS < 1

When using the SRM you apply a factored shear strength based on the shear strength of the soil divided by a strength reduction factor (SRF). For soils defined using cohesion only: cohesionfactored = cohesion/SRF. Now you can see that if you chose a SRF=0.7 the slope may be marginally stable as the factored shear strength is now greater than the true shear strength of the soil. You would say that the factor of safety of the slope equals the SRF associated with instability which is commonly defined at continuing displacement or non-convergence of the model. For your own information you might track displacement vs. SRF by choosing a point in the model to track as you continue to increase the trial SRF from some safe value towards instability.

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


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