OSHA 10-Hour Construction ReviewExcavationsHard
A competent person identifies a trench where a protective system is needed. The trench is 8 feet deep, and the excavation area is confined, making sloping impractical due to space constraints. What would be the most appropriate protective system for this scenario?
- AShielding, to protect workers from potential collapse.
- BBenching, as it reduces the required footprint.
- CSloping, using the maximum allowable angle for the soil type.
- DShoring, to support the trench walls actively.
Show answer & explanationAnswer & explanation
Correct answer: D. Shoring, to support the trench walls actively.
When space is confined and sloping is impractical, shoring becomes the most appropriate method. Shoring actively supports the trench walls, preventing collapse, and is effective in tight spaces where the excavation cannot be opened up. While shielding protects workers, shoring actively *prevents* the collapse, which is often preferred when space is limited and active wall support is needed.
Why the other options are wrong
- A. Shielding protects workers but does not prevent the trench walls from collapsing. In a confined space with an 8-foot depth, actively preventing collapse through shoring is generally a more comprehensive solution if feasible.
- B. Benching also requires a significant amount of space, making it impractical in confined areas just like sloping.
- C. The scenario explicitly states sloping is 'impractical due to space constraints,' ruling this out.
Shoring for Confined Excavations
Shoring systems are ideal for excavations in confined areas where there isn't enough space for sloping or benching. They actively support the trench walls to prevent cave-ins.
- Suitable for tight or confined spaces.
- Actively supports excavation walls.
- Prevents soil movement and collapse.
- Can be hydraulic, pneumatic, or timber systems.
Memory trick: Space, Soil, Safety Guide Selection