Underpinning existing footing with new column footing

[vhmehta]

I have a new column next to existing wall and am providing a new footing to pick up column load as well as wall load. I am extending the new footing below the existing footing to extend for the full width of existing footing. I am providing reinforced concrete footing below existing wall footing. Is it possible to construct the new footing in segments?

 

[North2South]

You certainly can’t build it all at once! You’re looking at doing 4 foot segments spaced about 20 feet on center when underpinning a foundation.

 

[oldestguy]

It is done all the time. I'd use some form of load transfer from old to new underpin sections. I've had the contractor leave a space between new underpin sections and base of old footing and then dry pack a stiff mix in that cavity hopefully taking up some of the load. Have heard of no problems that way. Run re-bars out in space for next underpin section to tie things together. Not an easy job with them in the way of next section. Stagger the underpin section locations. Bracing with tight sheeting (horizontal pieces) in all excavations below footings.