AEI - Architectural Engineering Institute

The bars on the soil side of the wall should be turned outward, that is toward the heel.  Turned the other way gives a crack an opportunity to evade the bar and follow the bend rather than cross the bar.  Some Swedish tests gave the inward turned case only about 60% of the nominal capacity, the other way 94% or more.

Nilsson and Losberg, "Reinforced Concrete Corner Joints Subjected to Bending Moments," Proc. ASCE, Jour. Struct. Div, Vol. 102, No. ST6, June 1976, pp. 1299-1254.