When should the actual slope be less steep than the maximum allowable slope?

The actual slope should be less steep than the maximum allowable slope when signs of distress are observed because this indicates potential instability in the soil or surrounding areas. Distress signs may include cracks, slumping, or erosion, which suggest that the existing slope may not be able to support itself safely. By maintaining a slope that is less steep than the maximum allowable, operators can reduce the risk of landslides or soil failure, enhancing safety for both workers and nearby structures.

The suggestion that this should only occur during heavy rains does not account for other factors that can lead to distress. Likewise, while it may be necessary to start with a less steep slope at the beginning of excavations to ensure safety, the key factor is the observation of distress itself, which warrants immediate attention to slope stabilization. Finally, after construction is complete, the need for a less steep slope would depend on final inspection and environmental factors rather than preemptively adjusting based on distress signals.