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!

*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.

Jobs

H-25 Loading

H-25 Loading

(OP)
I am designing a cement-treated base (CTB) using the PCA design guidelines for a pavement over soft ground.  The subgade will be a silty soil.  I was asked by the PM if my design included AASHTO H-25 loading and now I understand it has to do with how axle loads are transferred to drainage structures (culverts?).  The road is rural and most of the heavy traffic is 56,000 pound 4-axle gravel dumptrucks with a tandem axle (the fourth axle is retractable).

The PCA design procedure uses the fatigue factor to estimate CTB thickness.  Does the AASHTO H-25 load diagram apply to the fatigue factor calculation?  

   

RE: H-25 Loading

The AASHTO H-25 loading is a fictitious theoretical design truck.

Here is a primer on AASHTO pavement design that hopefully will help:

http://training.ce.washington.edu/wsdot/

Many other resources are also available online. Google "AASHTO pavement design"

Jeff
 

RE: H-25 Loading

In bridge design we normally use HS-20 loading, and if we were asked to use HS-25 loading we would have a corresponding increase in the fatigue distress.  You may need to increase your fatigue values by 25% in this case.

RE: H-25 Loading

Since you are looking at a pavemet, not a structure, you may have better luck looking at ESALS, not H-loading.

How many ESALS per HS-25?

     "...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

 

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


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