Which factor is crucial in evaluating the stability of a gravity wall?

The self-weight of the wall and the earth above is a fundamental factor in evaluating the stability of a gravity wall. This type of wall relies on its weight to resist lateral earth pressures and prevent overturning or sliding. The stability of a gravity wall is influenced by the combination of the wall's mass and the pressure exerted by the soil it retains.

As the wall holds back soil, the forces acting on it include the lateral earth pressure from the retained soil and any surcharge from above. The self-weight of the wall contributes to its resistance against these forces, ensuring the wall remains stable and does not fail under the conditions of load.

While other factors such as the height of the wall, type of soil at the base, and material composition are important considerations in wall design and performance, they do not directly provide the essential aspect of stability as effectively as the self-weight of the wall and the earth above. The interaction between these weights is key to maintaining equilibrium and ensuring the wall can safely support the conditions it faces.