Res 8 Trench Flashcards
How many people die in trench collapse each year
over 100 people
How many people are injured at jobsites each year
People 1,100
What is a cave in
the collapse of unsupported trench walls
What is an excavation
an opening in the ground from a digging effort
What are ground pads
Material used to distribute weight and forces over their surface area and minimize creating a secondary collapse
Secondary Cave In
a collapse of another portion of the trench after the initial accident has occurred
Sheeting
Wood planks and wood panels that support trench walls, held in place with shoring
Shoring
Lengths of timber, screw jacks, hydraulic and pneumatic jacks to hold sheeting against walls. Individual supports are called shores, cross braces, and struts.
Slough-in
collapse of portion of trench where an overhang remains
Spoil Pile
mound of material removed from an excavation
Tension Cracks
cracks in ground adjacent to trench, indicate ground has shifted
Definition of a trench
An excavation that is deeper then it is wide OR A temporary excavation in which the length of the bottom exceeds the width.
Trench is limited to excavations that are
less then 15 feet wide at the bottom and less then 20 feet deep
Trench lip
the edge of the trench
Uprights
Planks that are held in place against sections of sheeting with shores. Uprights add strength to system. Distribute forces exerted by trench wall and counterforce exerted by shores over wide areas of sheeting
