Trench collapse Flashcards
How much can a cubic meter of soil weigh?
1.25 tonnes
What are the signs of a trench collapse?
Deflection of supports
Distortion
Tension cracks
Soil movement
What are methods used to protect against trench collapse?
Sloping and benching
What is the process called where water content in soil increases to such an extent that the soil loses all cohesiveness and strength?
Liquification
The need to minimise minimise any vibration is key to prevent further collapse, what are examples of how this is done?
Spread the load using trench sheets or plywood
Isolate nearby heavy machinery
Park appliances away from the trench site
Relocation of loads e.g. building materials
Commit the minimum number of people to the hazard
It is important to ensure that fire service activity doesn’t worsen the collapse. What actions should be taken to prevent this?
