Re: Rubble wall reinforcement
Perhaps it's just me --- your description of the site and what is trying to be accomplished are difficult to picture. However, it seems you want to do some excavating and construct a deeper section of basement near the existing rubble stone foundation?
You need to hire a structural enginner to evaluate the site conditions and what is the best course of action to follow along with structural materials will be used and proper tie in to existing foundation. As well you will need certified drawings to submit for a permit ---- this is one project that needs a permit and inspected.
I'm not sure what you mean by ..........
" Can I pour in stages side ways to form a wall. "
" I have heard of "slurry Wall" construction.
Is this a viable option over underpinning the house and replacing the rubble with a poured foundation? "
.......... slurry walls are not structural. Perhaps you're thinking of pumped concrete?
To be honest, this is one project that should be handled by an experienced contractor ---- it's really not for a DIY'er.
Just some thoughts.
"" an ounce of perception -- a pound of obscure "