Smart questions
Smart answers
Smart people
Join Eng-Tips Forums
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • 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!

Join Eng-Tips
*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 from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

GeoGab (Geotechnical) (OP)
18 Apr 06 19:54
An engineer asked me a suggestion on the type of foundation to adopt for the enlargement of a building on a hilly slope. The foundation of the old part of the building is constituted by beams on silty clays. The ground of foundation of the new part shows a changement; in fact  there are fessurates clays . Some buildings around there founded over this kind of clay have brought some small lesions. Is it possible to adopt another type of foundation (to es. piles) for the new part in comparison to the old part, considering that both of them will settled up to constitute an only one building?
Thanks for the collaboration.
DaveAtkins (Structural)
20 Apr 06 9:01
I would get the recommendations of a Geotechnical Engineer, but if you are going to use two different types of foundation system, then a complete separation of the two structures would be required, in my opinion.

DaveAtkins

Helpful Member!  Panars (Geotechnical)
24 Apr 06 16:48
When adding to an existing building supported on spread footings in soil, you should keep in mind that the existing building may have already settled due to consolidation.  If you place the new structure on the same type of foundation, it will probably settle and there will be relative displacement between the two structures.

However, if you can support the new structure on piles to rock so that there is very little settlement, then there will be little relative movement between the structures.  This is common practice for widening bridges in my area.
GeoGab (Geotechnical) (OP)
25 Apr 06 7:21
The problem is that the bedrock in that area is very deep so it's impossible to do piles reaching the bedrock (there are only clays).
Thanks for yours answers!
Mccoy (Geotechnical)
28 Apr 06 11:32
Geogab,
in your area, that I know pretty well, you can still drill large diameter piles and have them work mainly by lateral friction.
It is not necessary to reach rock (it's about two thousand meters below!) , just a firmer layer beyond surface colluvium, at a suitable depth, since the loads you're dealing with are pretty small.
Panar's suggestions still hold. In my opinion that's your best choice, albeit, alas,  not the cheapest.

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!

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