×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• 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.

# How Do I Determine the Force of Flowing Water

## How Do I Determine the Force of Flowing Water

(OP)
I need to analyze a pipe hanger that will be located along the bottom of a bridge.  I need to determine what force the river flow will have on the pipe during a flood.  I've been told to use 3 fps as the velocity of flow.

The pipe is 8" and carries water.  I've been racking my brain but can't seem to find the correct formula.

Thanks for any help.

### RE: How Do I Determine the Force of Flowing Water

Grab your old hydraulics book and look through the momentum equation, etc...  You may have to derive the procedure inorder to fully understand it.

### RE: How Do I Determine the Force of Flowing Water

Momentum will give you a force at various points.  You will then have to analyze torque/moment and compare to pipe material specs.

But first, work on that velocity...use a flow versus cross sectional area analysis.  For that you will need depth.  For that, Manning's on the section might do, but I would do a HECRAS run on it.  During your design flood, the water most likely will greatly exceed 3 fps.  That is the most important prerequisite.  I don't think you should seal your conclusions without a better velocity.

### RE: How Do I Determine the Force of Flowing Water

What about ice floes? They have ripped more stuff from under bridges than just water. They bring an impact, point load to the party. Then think about debris.

### RE: How Do I Determine the Force of Flowing Water

not just ice, how about other floating debris such as trees?

### RE: How Do I Determine the Force of Flowing Water

(OP)
Thanks for the response.

#### 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.

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:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!