×
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

How to model the soil

How to model the soil

How to model the soil

(OP)
I am designing a water retaining structure and I need to know how to model the soil under the structure to see the soil stresses. pl help me on this regards.

Thanks you in advance
 

RE: How to model the soil

Good question Lassa88

but there is no harm if you do a little theory yourself. You can APPROXIMATE soil by using springs.

The value of spring you should input into SAP2000 is calculated as follows

1-Determine the soil stiffness in kN/m3 or ton/m3 of lbs/ft3 whatever units

2-Multiply this by the area represented by the node where you want to put the spring, this gives you kN/m or ton/m or lbs/ft etc.

 This is really a crude approximation and you wont get results more superior than you would get doing some manual calculations.

And there is a trap. If your spring reactions are negative, the model becomes wrong. Make sure you dont have spring reactions with uplift, since real soil can not tolerate that

And another trap: If your loads are seismic, spring stiffness determined above is questionable.

What elements will you use to model the tank? shell elements?


respects

ijr
 

RE: How to model the soil

(OP)
IJR,
It is really helpful and as you said I need to study some text book. Yes, I have used shell element to model the Intze type tank. Anyway I have some questions on this regards and hope to come back soon. I hope you will help me again.
With Regards
Lasa
 

RE: How to model the soil

you can use areas and then assign a spring stiffness to that area.  You even can make the springs compression only...draw the area and then assign what you require

RE: How to model the soil

Hey Lasa88,

I have recently encountered a similar problem with yours, modeling the soil in order to find out the stresses, and I did it using solids. I assigned the appropriate material properties to the solids and i was able to see the stress distribution after the analysis.
I might add it's a bit time consuming and I am still in the process of validating this approach.

Cheers,
iotoma

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