Does it leak all around the perimeter of the basement or just in one spot?
Basement leaks like the one you describe are caused by an over saturated soil around the foundation. That soil which was once dug for the basement to be built and then back filled is not as hard packed as the unexcavated portion of the land. It acts like a sponge. When soaked with water, the resulting hydrostatic pressure causes the water to seep in through any opening it finds, usually in that joint between wall and floor.
Heavy rains will normally cause that over saturation, which is why houses are built with a french drain or drain tile usually buried by the foundation footing.
Here's a few things that might be happening there:
1 - The terrain around the foundation walls should be sloping away from it, and the new patio should be either sloping too or have some sort of drainage that will allow the rain water to be discharged far away from the foundation.
2 - Was there any change on extension and placement of downspouts, in order for the basement to be built? Extend the downspouts as far as possible from the walls and make sure the gutters are clean.
4 - The french drain is clogged or collapsed which might be completely unrelated to the patio project. External drains, sometimes clog with mud and debris, specially during heavy rains.
See if after extending downspouts, cleaning gutters, grading and fixing surface drainage things improve in any way.
If they don't, I'd recommend you install an internal drainage system along your basement walls, to collect the water around the foundation and divert it to a sump pump. It works much like the external drain tiles with a few advantages:
- You will not need to break down your newly poured patio to dig out the foundations and install new french drains
- Internal drain tiles are serviceable and should they clog, you can just flush the system.
- They cost 50% less than conventional drain tiles.