#1
What is the primary purpose of using trench boxes in excavation?
To prevent cave-ins and protect workers
ExplanationTrench boxes are used to shield workers from cave-ins by providing a protective barrier within the trench.
#2
Which of the following protective measures is used to prevent cave-ins in excavation work?
Trench shields
ExplanationTrench shields, also known as trench boxes, offer protection by surrounding workers within a steel structure, preventing cave-ins.
#3
What does the term 'sloping' refer to in excavation safety?
The angle of incline provided to excavated walls
ExplanationSloping involves angling trench walls away from the excavation to reduce the risk of collapses, ensuring worker safety.
#4
What does the term 'benching' refer to in excavation safety?
Creating horizontal levels in the excavation walls
ExplanationBenching involves cutting the trench walls into horizontal steps or levels, providing stability and minimizing the risk of collapses.
#5
Which of the following is a common hazard associated with excavation work?
Trench collapse
ExplanationTrench collapse poses a significant risk to workers' safety by burying them under soil and debris.
#6
What is the minimum slope requirement for excavation walls to prevent collapse?
1:1 (45 degrees)
ExplanationA 1:1 slope, or 45-degree angle, helps stabilize excavation walls by minimizing the risk of collapse.
#7
What is the purpose of shoring in excavation safety?
To strengthen the excavated walls
ExplanationShoring systems reinforce trench walls, providing temporary support to prevent collapses during excavation operations.
#8
Which agency in the United States is responsible for regulating excavation safety standards?
OSHA
ExplanationThe Occupational Safety and Health Administration (OSHA) sets and enforces safety standards to protect workers during excavation activities.
#9
Why is it important to call for utility locates before starting excavation work?
To avoid damaging underground utilities
ExplanationUtility locates prevent accidental damage to underground infrastructure, such as gas or water lines, which could lead to hazardous situations.
#10
What type of soil is considered the most stable for excavation?
Clay
ExplanationClay soil provides better stability due to its cohesive nature, reducing the risk of collapses during excavation.
#11
What is the main purpose of conducting soil testing before excavation?
To determine the type and stability of the soil
ExplanationSoil testing helps assess soil conditions, identifying potential hazards and selecting appropriate safety measures to ensure excavation stability.
#12
Why is it essential to establish a confined space entry program for excavation projects?
To monitor air quality and ensure worker safety
ExplanationConfined space entry programs oversee atmospheric conditions within excavations, safeguarding workers from hazardous gases and lack of oxygen.