If you design the friction pile such that you ignore the contribution of friction over the length of pile within the influence zone of the wall, then generally you do not need to worry about any surcharge.
Generally these spot loads are taken care of by the safety factors and the fact the loading spreads out over a distance depending on load and proximity. The only on-site work needed is careful observation of the wall's "straightness".
Maybe you could calculate the amount of the pile's side friction that is above the bottom of the wall and then consider that total friction as a point load on the ground surface behind the wall using Boussinesq's equation for a point load. Or just consider the amount of pile friction that is on the pile length that is above an influence line that extends up from the bottom of the wall at about a 45 degree angle.
