Hazards in Excavation Work

What is one of the hazards involved in working in trenches?

• Excessive noise

• Collapse of the sides of the excavation

• High temperatures

• Lack of oxygen

What can cause people and vehicles to fall into the excavation?

• Poor lighting

• Lack of signage

• People and vehicles falling into the excavation

• High winds

What can ingress of water cause in an excavation site?

• Improved soil quality

• Flooding

• Increased temperature

• Reduced humidity

What can cause flooding in an excavation site?

• Ingress of water

• High temperatures

• Excessive noise

• Lack of ventilation

What is a necessary condition for safe trench work?

• Ignoring safety protocols

• Awareness of hazards

• Increasing work hours

• Reducing workforce

What is the benefit of having the top half of the body free in a trench collapse?

• Easier to dig out

• Breathing is not restricted

• Faster rescue

• Less dirt to remove

Which of the following is NOT a method for trench side support?

• Benched

• Battered

• Supported by a walling system

• Filled with water

Which of the following is a method to ensure trench safety?

• Filling with water

• Using a support system

• Painting the sides

• Reducing the width

When are trench supports or shoring used?

• When the trench is very deep

• When no other method is practicable

• When the soil is sandy

• When the weather is rainy

What factor influences the choice of trench support method?

• The color of the soil

• The type of excavation

• The time of year

• The size of the construction crew