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

Grouting in vertical fissures in rock

Grouting in vertical fissures in rock

(OP)
Isn't the resultant fluid force on a vertical boundary limited by the volume of fluid available to exert the force?

I am going to use an example of a fissure in rock but the same could be said of a retaining wall with a finite amount of flowable material behind it, for example a wall cut into rock with a narrow zone of structural backfill behind the wall face.

Let's say one has a vertical fissure in impermeable, unsaturated rock and one wants to grout the fissure to stabilize the column of rock between the fissure and a nearby free surface. While the grout is still fluid, the fissure walls will theoretically be subjected to a hydrostatic pressure per unit of wall length equal to 0.5*(height^2)*fluid unit weight. For example let's say (for simplicity) the grout has the density of water and the height is 10 ft; then the theoretical horizontal fluid pressure on the fissure walls is 0.5*62.4*100 = 3120 lb/LF of fissure. Now let's say the fissure is only 1 inch wide. It contains only 1/12*10*62.4 = 52 lb/LF of fluid. As I said the fissure contains fluid, but the walls are dry and impermeable, so there is no hydraulic communication between the fluid in the fissure and any other fluid level.

I see these analyses all the time where the hydrostatic pressure is used, even though it exceeds the weight of the water available to exert it?

Am I missing something here?

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