basement for existing structure

huangyhg

basement for existing structure
we need to install a water proof basement under an existing buildings wall, probably using structural steel frame:
natural clay becoming firmer with depth at 7 ft from ground level
objective is to avoid having to shore up the walls, if possible.
has any one experience of the following method
1.    placing a pillar outside and at each end of a wall
2. inserting girder connecting pillars
3. internal support pillars where necessary
4. do this for all walls to create supporting structural load baring frame
are there alternatives?
jon
jon:
what is the physical size of the existing building? is it a single/double storey? what was it is made of?
this is a tradional brick building with slate roof:
ground approx 1,800 sq ft and two other stories above

total including ground is approx 3,000 sq ft.