I had the misfortune of hiring an incompetent architect (and builder). One of the primary load bearing floor beams (20x45cm with 10 pcs 16mm rebar) ties into another lighter load bearing ring beam (20x40 cm with 6 pcs 12 mm rebar) mid-span. That is, there is no supporting column at the juncture of the two beams.

These beams (among others) support a suspended reinforced concrete floor 10cm thick, and the larger beam spans a distance of 10 meters. It is unsupported except for a single supporting column at one end and the lighter ring beam it ties into, mid-span, at the other.

I am sure it is only a matter of time before the lighter ring beam fails unless something is done to reinforce it. I presume it is possible to build a support column after the fact, but would like some expert advice on the best method to do this. If a column is added, what is the best way to tie it into the existing beam?

How about a picture or sketch to better understand the setup.

Hope this helps.

http://i819.photobucket.com/albums/zz111/lacogada/floorbeam_zpsadd7d62b.jpg

About 30", maybe a bit more.

If you have concerns, setup a temp support. Just set it back far enough that you have room to work on permanent support.

2' x 2' concrete pad.
3 - 8x8x8 or 8x8x16 cinder blocks.
Couple pieces of 2 x 6 or 2 x 8.

That should get you about where you need to be.
If the 2 x blocks come up a little shy of the existing beam, cut a couple of wedges and drive between the 2 x blocks and existing beam.

http://i819.photobucket.com/albums/zz111/lacogada/supportbeam2_zpsdc0685bb.jpg