[REQUEST] STRENGTHENING OF FOOTING

[knrsa]

If any have sample calculations for strengthening of footing as shown in figure above.
Please share it.

thanks

[ykhackhack]

@knrsa

Please indicate your problem with specifics. Like, what is the column size, load and footing size and loadings

The reason for the footing retrofit.

Level of detailing and calculations depend on these specifics.

If you have only one footing to repair, you would do it conservatively because the cost engineering time will exceed the repair cost

Or if you have too many of these footings , it might offset the engineering cost.

The location of these footings are also important, located at inside or outside of the building can effect the detail

Basically the detail / arrangement you are showing is correct.

Regards

[knrsa]

Dear ykhackhack
Thanks for reply to my quarry.
Reason was footings are designed for 300 kN/m², without investigation footings are casted. After investigation it is found that the actual SBC is 150 kN/m². Due to this eight number of footings required strengthening.
All footings are located inside the building.
Regards

[ykhackhack]

@knrsa

We do these types of retrofit to the old foundations.

For example ,if we want to add another floor on top of an existing.

Please be more specific about the column and footing sizes and the loads also

What is the stage of the construction at the moment.
(By the way 300 kN/m^2 , which is more than 6000 psf is very dense soil)

Main design criteria here is to transfer shear and flexural forces ar intersection surfaces of old and new concrete.

Using epoxy bonding agent (like SIKA products, to bond old concrete to fresh concrete ) would make the design work better.
Regards

[knrsa]

Dear ykhackhack
If you have sample calculation notes please share. Hope I have given you the all information
you required.
Thanks&Regards

[learner20]

Hello knrsa
Try finding books related to retrofitting/repair especially column and footing jacketing
I feel jacketing is the option , but you need to provide the building plan with all columns+plus all loads so that expert here can try to find the solution
Bye

[88FeNIX]

Dear knrsa,
There are only two main considerations Flexure and Shear.
You just need to focus that the additional shear and flexure is catered by making sure that a perfect connection exists between old and new footing.

I have attached an image of detailing. Hope it helps as I dont have the calculations right now.


Moderator note:

Your image realy help. Try to learn how to post the uploaded image if you want someone see it without effort.