Inclined foundation

[ksdphilippines]

G'day All!

Just would like to enquire if anyone can lead me to specifications or concepts on:

1.) Effects of soil inclination to foundation eg: soil is inclined and footing is inclined along it.
- doing some experiment with foundation and i have to incline a footing along the grade of the soil.

2.) anything on inclined foundation or footings!


Cheers!

 

[JackTrades]

NAVFAC DM 7.02 can be found at:

http://www.politecnicovirtual.edu.co/Fundaciones/Foundations and Earth Structures.pdf

Thank SlideRuleEra. He provided this link on another thread.

-Jack

 

[jike]

Obviously, the footing bearing on a sloping surface will have a tendency to slide. Frictional forces times a safety factor need to be sufficient to prevent sliding. You could also create a key or several keys on the bottom of the footing to increase the resistance to sliding.

 

[PMR06]

G'Day to you as well. Australian? If you are in the US, I think IBC 2003 section 1805.1 limits the slope of the bottom of a footing to 1:10. I'm not sure what the requirement for footings would be "down under" (pun intended!).

 

[csd72]

Struth, lets get out the didgeridoos and have a coroboree!

Anyhow, you are much better stepping thefoundation than to slope it, a flat surface is easier for the builder, and avoids that messy sliding issue.

 

[apsix]

If it is a reinforced beam I would detail the rebar cage with parallel top and bottom bars, and form the steps to underside (and top if required) in mass concrete. This possibly won't work as well if the gradient is steep.

 

[ksdphilippines]

Cheers mate!

Yup, a footing problem down-under..

anyway, im actually designing a precasting (prestressing) bulkhead. A previous design had a triangular footing to counter the eccentric stressing load of 2400KN and used the friction / bearing of the sloping portion to take on the horizontal force ( fancy design ).

was checking whether i could do the same design or present a new one.

am looking into the merits of the previous design.

im also looking at a spread footing with bored piers anchors..

anyway, one more shot.. how much load factor should be given to the prestressing load ( deadload factor =1.2, live load =1.5 ) Im inclined to use 1.2 since the load is controlled and will not vary that much.. any thoughts on this?

Cheers!

 

[minorchord2000]

I would conservatively step the footing when the vertical change in elevation is 3'. I would hate to trust the stability of the footing on the frictional capacity of soil and passive pressure which may or may not be there in the future.