Overturning stability of retaining walls

The main defect in the traditional overturning stability analysis for retaining walls is discussed. It is pointed out that the main reason is the irrational premise of its theoretical analysis. A more rational overturning coefficient K0 is then derived by assuming that the vertical load on the retaining wall at the limit state is the same as the actual state of loading. The overturning stability coefficient is defined as the maximum anti-overturning moment provided by the retaining wall system divided by the overturning moment from the actual soil load. Using the new definition of overturning coefficient, it is shown that K0 increases with the increase of the ultimate bearing capacity of foundation soil and decreases with the increase of vertical load. It is also inversely proportional to the load eccentricity at the base. The overturning stability of a retaining wall is closely related to the stress state at its base. By comparing the requirements of bearing capacity and overturning stability in China's design codes, as long as the bearing capacity of foundation meets the design requirements, the overturning stability can be guaranteed, and it is not necessary to individually check the overturning stability.