×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

*
*
*
*

Thanks. We have received your request and will respond promptly.

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

Soil spring stiffness

thread256-484148

Soil spring stiffness

Soil spring stiffness

(OP)
Hi,

I have read thread256-285800: Spring Stifness and got stuck here:
"If you look at Bowles Table 9-1, modulus subgrade, kv (kN/m3)
approx equal to 240 Cu (kPa).
Allowable bearing pressure, qa (kPa) = Nc Cu / SF = (5.14 /3) Cu..."

Bowles Table 9-1 shows ks (not kv), and there is no Cu there...
Also, where is the 5.14 value coming from?

Thanks.

RE: Soil spring stiffness

Nc is bearing capacity factor of 5.14. This is for phi = 0

RE: Soil spring stiffness

(OP)
Thanks, EireChch - where could I find a reference for this?

So for phi=0 (cohesive soils) use Nc=5.14, but what if c=0 or for c-phi soil types?

RE: Soil spring stiffness

Any soil mechanics/ foundation book (bowles) that has a section on bearing capacity shows Nc values for phi = 0 to phi = 40+. Its a row of tables.

c is typically taken as 0 in c-phi soils as it is conservative (generally).

When c = 0 the first part of the bearing capacity equation is ignored. The second and third parts, which includes Ngamma and Nq are used to calculate bearing capacity.

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

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