A surcharge load is an additional retaining wall load superimposed onto the earth pressure force to yield the total lateral force.
The TOTAL REACTIONS are also calculated.
You may also be interested to see this other download relating to surcharge loads.
Craig's Soil Mechanics
Retaining wall design
Full download access to any calculation is available to users with a paid or awarded subscription (XLC Pro).
Subscriptions are free to contributors to the site, alternatively they can be purchased.
Click here for information on subscriptions.