×
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

Thrust Block Design
5

Thrust Block Design

Thrust Block Design

(OP)
I need information about the thrust block design procedure.  In one side I have the momentum formula, and in the other side I have this formula T=2PAsin(phi) where “P” is the pressure, “A” is the pipe cross section area where the flow goes, and “phi” is the bend angle.  Is the last formula a "rule of thumb" for the thrust block design?  Using this formula, an engineer calculated 10 concrete trucks to build a thrust block for a 45 degrees, 48inches, vertical bend, and using the momentum formula I get only 2 concrete trucks for the vertical thrust block.  The pressure (P) that he used was an assumed value equal to two times the working pressure for this pipeline.  The working pressure for this pipeline is 150psi.  So, at the end, the engineer is multiplying the working pressure by four!!  

I know... I know.  To design a Thrust Block I have to use the momentum formula and take in account the weight of the bend itself and the water inside the bend if it's a vertical thrust block, but I am a little confused with the engineer using that formula.  

I'll be grateful if someone of you show me an example on how to design a vertical and horizontal thrust block.

Thank you for your information.

RE: Thrust Block Design

2
Have you checked the example used in the DIPRA publication on thrust restraint design?

RE: Thrust Block Design

2
Suggest you check out the following reference: "Pipe Restraints: Design Fallacies" by Patrick J. Creegan, F. ASCE which appeared in the Journal of Transportation Engineering, Vol. 109, No. 6, November, 1983.  This peer reviewed paper will give you clear definitive guidance and several worked examples.

RE: Thrust Block Design

If you have not found the information needed,contact me I can put you in touch with an engineer that has designed pipe systems for twenty years.

NEC,WWW.NATIONALEROSION.COM

RE: Thrust Block Design

DENIS

Can you tell me where I might be able to get a copy of the "Pipe Restraint....." paper?

Thanks,


John

RE: Thrust Block Design

better yet, do what most agencies are doing now, and eliminate the thrust block altogether.  Restrain the joints!  For a 48" pipe, this is a better idea.  Sure, it's easier to just dump a bunch of "cement" in there - and a lot easier than installing those expensive mechanical joints, - but what a mess if you ever have to dig up those 10 truckloads of concrete.

 Chuck
 cgopperton@stantec.com
 http://www.stantec.com/
 

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