Massachusetts Hoisting License Practice Test

Which type of soil requires shoring when working in a trench?

1. Type A

2. Type B

3. Type C

4. Type D

The correct answer is: Type C

Type C soil is characterized by its granular composition, which typically includes sands and gravels that can be subjected to significant movement and collapse when disturbed. The cohesion in Type C soil is very low, presenting a higher risk for cave-ins, especially in trenching operations. This necessitates the requirement of shoring systems or additional support structures to ensure the safety of workers operating in or near the trench. Understanding soil classifications is crucial for safe excavation practices. Type A soil, which is the most stable, generally does not require shoring unless the trench depth exceeds 20 feet. Type B soil presents moderate stability and may require shoring depending on various factors, such as depth and trench conditions. Type D soil, though not explicitly classified in standard soil types, typically indicates problematic soils that may be prone to instability. In summary, Type C soil’s properties necessitate the implementation of shoring to prevent hazardous conditions during trench work. This knowledge is vital for maintaining safety standards in excavation activities.