×
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

Soil Properties from RQD?

Soil Properties from RQD?

Soil Properties from RQD?

(OP)
I am designing a short (6' and less) Reinforced Earth wall in a cut situation.  The reinforced fill will be crushed stone to minimize the reinforceing embedment length.  

The retained material is a poor quality limestone, with an RQD (Rock Quality Designation) of 8 to 25.  A Texas Cone Penetrometer advanced 0" at 100 blows.  

Does anyone have any reccomendations as to what phi angle I should apply to the retained material?  Would a value of 36 to 38 be appropriate?

Thanks in advance.

RE: Soil Properties from RQD?

[Focht3 shouts from atop his soap box]

Since you used the Texas cone, this project must have TexDOT money!  No self-respecting geotechnical engineer uses it - but we must do the @#%&?! test on TexDOT jobs!!  [calmer] You have my condolences. [aggravated again] Why do "they" insist on using this damn tool in rock?!  It's stupid!

[Focht3 descends from his soap box]

Where is your site? (I'm in San Antonio.) How does the aggregate classify (per TexDOT)?  How angular? What is the clay fraction and/or PI?

My initial reaction is to use only 32 or 33 degrees - the wall is short.  Do you have an encroachment problem?

RE: Soil Properties from RQD?

Focht3:  I love your comments!!!  I am narrowing you down!!  My sister is in San Antonio - working for A&M extension program services.  Just got her Ph.D.  Proud of her for that.  See my question, please, on minimum unit weights for fills in "earthworks".  Best to you.

RE: Soil Properties from RQD?

You indicate that you are in poor quality limestone, I would agree with Focht3, a lower value is more conservative.  If it is rock then the materials are retaining themselves, did you do any coring, this could give much better qualties to the internal phi angle of the rock.

ITS LIMESTONE, be more worried ABOUT sinkholes!!!! USe a more conservative phi angle.

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


Resources

eBook - Simulation-Driven Design with SOLIDWORKS
Simulation-driven design can reduce the time and cost of product development. In this engineering.com eBook, we’ll explore how SOLIDWORKS users can access simulation-driven design through the SOLIDWORKS Simulation suite of analysis tools. Download Now
eBook - Integrating the Engineering Ecosystem
Aras Innovator provides multiple options for integrating data between systems, depending on the scenario. Utilizing the right approach to meet specific business requirements is vital. These needs range from authoring tools, federating data from various and dissimilar databases, and triggering processes and workflows. Download Now
Research Report - Simulation-Driven Design for SOLIDWORKS Users
In this engineering.com research report, we discuss the rising role of simulation and the paradigm shift commonly called the democratization of simulation. In particular, we focus on how SOLIDWORKS users can take advantage of simulation-driven design through two analysis tools: SOLIDWORKS Simulation and 3DEXPERIENCE WORKS. 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