What is the minimum increase in slope required by OSHA when there is a sign of distress?

The minimum increase in slope required by OSHA when there is a sign of distress is indeed 1/2 horizontal to 1 vertical (1/2h to 1V). This requirement is based on the need to enhance stability and reduce the risk of cave-ins during excavation work. A steeper slope that is less than 1/2h to 1V may not adequately support the earth structure, especially if there are visible signs of distress such as cracking or soil movement.

OSHA sets forth these guidelines to ensure that workers are not exposed to hazardous conditions. The 1/2h to 1V increase reflects a significant enough adjustment to improve the safety of the excavation and manage the forces acting on the soil. It is essential for workers and supervisors to recognize signs of distress and respond accordingly by adjusting the slope to maintain safety standards.