Worked examples of retaining wall design to BS8002
The following worked examples have been prepared to illustrate the application of BS8002 to retaining wall design. They are not full detailed calculations such as might be prepared for a real wall design but are limited to the calculation of earth pressure and bearing capacity, showing how the recommendations of BS8002 are applied in practice.
BS8002 introduces radical changes in the design of retaining walls. Traditionally, the forces applied to a wall have been calculated using representative values of key parameters such as soil strength and then safety and satisfactory service performance are ensured by applying suitable safety factors to the results of the calculations. BS8002 takes a completely different approach: there are no formal safety factors and instead safety and satisfactory performance in service are ensured by using applied forces and soil strengths which are conservative estimates, in order to produce what is effectively a ‘worst case’ analysis.
To assist understanding of the changes introduced by BS8002 and how they affect design, in the examples each wall is first designed in accordance with the traditional method (CP2) and it is then designed again in accordance with BS8002 and the results are compared. It is hoped that this will assist engineers changing over to the new Code, by showing how the new design method works and also giving some ‘feel’ for how it compares with past practice.