Retaining wall analysis & design (BS8002): Base resistance to sliding

The base resistance to sliding is in accordance with cl4.2.2.3 of 8002 which states you can either use the total stress (c_b - base adhesion) or the effective stress (delta_b - angle of base friction given in degrees), however this calculation only uses the base friction approach. Given that you know the plasticity index of the soil, Clause 3.2.6 gives you a way of calculating delta given phi and phi can be estimated via table 2 from the soil plasticity index.

It is our recommendation the above approach be checked against the code and verified as a suitable approach by the user