ACI 318 would probably be the best place to look. Treat the tieback as if it were a column/reaction point. Depending on your layout of your tiebacks you could treat it as a two way slab system or a 1 way slab system (depending on spacing vertically and horizontally). Using SAFE or other 2D FEM program will help determine moments. In the local area of the tieback you should check for punching shear and bearing.
If you are taking about soil nails though you should look at the FHWA manual (geotech circular)
The links that ishvaaag and I presented above are for soil nail walls, not tiedback walls. If you have a tiedback wall, then the tieback anchors are almost always attached directly to the soldier beams, whether thay are steel beams, drilled shafts, or secant piles. In that case, the wall facing is attached to the soldier beams, not to the tieback anchor heads. For steel soldier beams, the facing (whether cast-in-place or shotcreted) is attached to the soldier beams with welded, headed, tension studs. If using concrete drilled shafts or secant piles, the facing can be attached with rebar dowels.
PEInc is right about the soldier piles with welded studs. I typically design it as a 1-way slab between soldier piles using ACI.
If you are installing tiebacks in an existing concrete wall as a retrofit, then you would have to go through the ACI and/or Masonry institute design checks.
