F3 - LT#3 - Planning excavations and shoring Flashcards
What factors affect the depth of excavations for a building?
1) Building design/loading
2) Soil type and bearing strength
3) Climate
For big projects, what type of equipment is used to move large amounts of materials?
Caterpillar tractors, scrapers & large hoes
Why should water not be allowed to stand where foundations are to be placed?
It destabilizes and weakens the bearing capacity of soil
If gravity drainage is not possible, how should rain and groundwater be controlled?
Using sump or wells
What should be located before you dig?
Underground utilities such as gas, electricity and sewer.
List 5 safety precautions to be used while working around excavation equipment.
1) Stay out of the circle
2) Stay well back from the rear
3) Don’t walk under boom
Why are signs posted near a blast site?
So people are aware of the signals and warning procedures.
What do 12 short whistle signals indicate?
Warning preceding a blast
How long must a blaster wait before initiating the blast after the signal that warns of an impending blast?
Two minutes.
What is an “All clear” sound signal used during blasting?
5 second whistle.
What is used to prevent the public from falling in an open excavation?
Barricades and hoarding.
How deep can excavations be before a ladder is required?
4 feet. (1.2 meters)
What is the minimum width of walkways at excavations?
20 inches
How is the width of a strip footing determined?
By the type of soil that supports the footing.
When possible, should you save topsoil?
Can be re-used during landscaping
What should be done before the excavation process?
Locate all services that are in the area of the excavation. Shut off, or isolate hazardous services
Where do water services start from?
Enter below footings, below frost line, come up through basement floor close to a wall. Equipped with water meter.
What pipes are connected to the storm sewer?
Perimeter drainage tile and drainage from under the building foundation are connected to the storm sewer. Runoff from the roof is directed to the storm sewer through rainwater leaders.
Can you put a gas line under the driveway?
Usually, yes you can but it is expensive to rip them up if a leak were to occur.
Gas lines must be located, staked, installed and removed by:
Certified Gas Fitter
How do you avoid gas leaks in a house?
The gas line must be outside of the building and topped by a meter.
The electrical conduit must be about how far above the roof.
1220 MM so that no conductor is closer than 915 mm
Electrical conductors must be no closer than:
4575 from the ground above vehicle areas and 3660 MM from the ground otherwise
Service conductors are usually raised about:
5490 MM when accompanied by the telephone lines to avoid contact between them.
