Picking up a project where someone else left off.  I could use input on how to attach and brace interior stud walls to our ICF wall.

I need a wall to run parallel to the main outer wall.   There will only be one 5 ft perpendicular wall connecting the two.  The rest of the connections will have to be above the wall.   Stud walls can be glued but not anchored to the floor because they installed radiant floor heating and we have no schematics on where those lines lay.   We can probably find the lines later when the plumbing goes in, but the plumbers want walls in first so they have something to work with.  

Right now I basically have a wide open hexagon main area and I need this wall to be substantial because the side facing the main living area will have kitchen cabinets hung on it at a later time/date.   There is just one board for the top plate between the IDF and the roof trusses.   I was expecting more to work with and am worried that any anchors I use will sink into the foam if they drop below that one top plate board.

We use Simpson concrete anchors and foundation washers to fasten interior stud walls to ICF concrete. We use adhesive and Simpson concrete anchors and foundation washers to fasten the PT stud wall floor sills to the concrete slab, but we know the exact location and depth of the HR PEX tube in these locations. You don't need to go more than 1-2" into the slab concrete to provide sufficient shear strength to keep the walls from moving laterally. You shouldn't fasten the interior stud walls (or ceiling drywall close to walls) directly to the trusses. You should use truss plates and drywall plates to address truss uplift. Anyhow, hope this helps.

To securely attach a 2x4 stud to an iCF wall, you can drill through the stud, foam, and into the concrete with a 1/2" rotary hammer drill bit, then drop in a 1/2" Red Head anchor bolt of sufficient length, and tighten. You will need about an 8" long anchor bolt assuming 2.5" depth into the concrete, 2.5" of foam, and 1.5" of wood stud, plus ~1.5" beyond the stud for the nut and washer. You would need at most 2 of these anchors; one near the top of the stud and one near the bottom.

For the long wall top attachment to the trusses, they make special truss clips that allow vertical movement of the trusses, but limit horizontal movement of the wall.

Gluing down the wall bottom plate is probably sufficient if you use a good grade of construction adhesive like PL Premium. But you can come back after the water lines are identified and set some 1/4" x 2-3/4" Blue Screw Tapcons through the bottom plate into the concrete floor with ~1-1/4" embeddment in the concrete after the wall is up. Just drill through the bottom plate into the concrete with a 1/4" concrete bit in a rotary hammer drill (i.e. Bosch Bulldog or similar), then set the tapcons with an impact driver.

1/4” x 6” long tapcons work just fine, unless you need major sheer support. For that you need anchor bolts.

This may be a bit late to help, but you might also want to check with your local or state specifications to see if you need a termite membrane barrier between the stud and the ICF.