Safety Trained Supervisor (STS) Practice Exam

When removing shoring from a trench, in what direction must the process be performed?

1. side to side

2. top to bottom

3. bottom to top

4. in a zigzag pattern

The correct answer is: bottom to top

Removing shoring from a trench should be performed in a bottom-to-top manner to ensure the safety and stability of the trench. This approach allows for the gradual release of the pressure on the soil walls, reducing the risk of a collapse as the shoring is removed. Starting from the bottom helps to maintain the integrity of the trench walls while lessening the potential for sudden shifts in soil that could occur if the shoring were removed from the top down. By carefully dismantling the shoring from the bottom first, you can effectively control the removal process, ensuring that the trench remains safe for workers who may still be inside or nearby. In contrast, other methods such as removing shoring side to side or in a zigzag pattern can lead to uneven pressure on the trench walls, increasing the likelihood of a collapse. Thus, the bottom-to-top method is the recommended practice for these situations.