×
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

Rectangular Concrete Tank: Stability Forces

Rectangular Concrete Tank: Stability Forces

Rectangular Concrete Tank: Stability Forces

(OP)
I've posted this in Structural already but really would like some foundation/soils people to comment too:

I am reviewing the sliding stability of a 16'x14'x17'-deep concrete tank. Essentially, it will need to behave as a retaining wall during a possible future installation of an adjacent tank. There will be full height soil on one side and full excavation on the opposite side of the tank.

When I check the sliding stability for this case I get a S.F. = 0.74. Increasing the slab doesn't add enough weight to increase the S.F. by much.

I am hoping to use the friction between the soil and the SIDEWALLS to help pump-up my S.F. > 1.5. However, I can't find any information concerning how to adequately calculate this resistance.

My guess would be to use the Friction Angle for Dissimilar Materials from AASHTO (typically used in calculating the vertical component of Coulomb lateral earth pressures) to get a corresponding friction coefficient for the walls. Then, multiply the linearly varying lateral soil pressure normal to the sidewalls of the tank to get a linearly varying friction resistance for the orthogonal direction.

Thoughts? Thanks!

RE: Rectangular Concrete Tank: Stability Forces

Hi US Engineer
I do not know the subsoil underneath your deep concrete tank with the SF of sliding= 0.74, it seem to be the soil is unsuitable for the direct footing.
I think the pile foundation will be another option for your tank foundation.

RE: Rectangular Concrete Tank: Stability Forces

Can you fill the tank with water during construction? That will greatly increase your normal forces and resulting sliding resistance.

RE: Rectangular Concrete Tank: Stability Forces

Your tank is not very large but is deep. I do not think it is very practical to think that the tank needs to be stable, on its own, during an adjacent, future excavation. In my experience, tanks are not designed for future, adjacent excavation. If an adjacent tank is to be built in the future, the contractor could install sheeting around the new tank area and brace this sheeting to the existing tank. With the first tank being only 14 or 16 feet long but 17 feet deep, the future tank's excavation would need to be a significantly sloped open cut if sheeting were not used. If there are adjacent underground utilities, the sloped open cut may not be possible. IMHO, designing the first tank to be stable during an adjacent tank excavation is a nice idea but expensive and not very practical.

www.PeirceEngineering.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! Already a Member? Login


Resources

White Paper - How ESI is Helping Move New Medical Device Product to Market Quicker & More Cost Effic
Early Supplier Involvement has long been a strategy employed by manufacturers to produce innovative products. Now, it almost seems like a necessity. Because decisions made in the design phase can positively affect product quality and costs, this can help add value to OEM bottom lines. This white paper will discuss many facets of ESI, including why it’s so valuable today, what challenges limit the benefits of ESI, how cost is impacted, and more. Download Now
White Paper - Moving to a Driverless Future
This white paper describes what we see as the best practices to support a sustainable engineering process for autonomous vehicle design. It exposes how to use simulation and testing in common frameworks to enable design exploration, verification and validation for the development of autonomous cars at a system, software and full-vehicle level to drive a mature product development process for automated driving. Download Now
Research Report - How Engineers are Using Remote Access
Remote access enables engineers to work from anywhere provided they have an internet connection. We surveyed our audience of engineers, designers and product managers to learn how they use remote access within their organizations. We wanted to know which industries have adopted remote access, which software they are using, and what features matter most. 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