The Earth Load dialog for this load case is modified from that the one available under regular pier design module. Select the generate dialog to open the earth load generation dialog and input the soil properties, i.e., unit weight of soil gamma and earth-pressure coefficient, Ka.

For pile cap design option, the height is the addition of backwall and stem.

In this case, pressure is calculated using ka*r*H and applied at the bottom of the pile cap. The total load is calculated as (1/2)*(Pressure*abutment length)*H. Program distributes this load equally at all bearings in Z direction.