F3 - LT#3 - Planning excavations and shoring

Question 1

What factors affect the depth of excavations for a building?

Answer 1

1) Building design/loading
2) Soil type and bearing strength
3) Climate

Question 2

For big projects, what type of equipment is used to move large amounts of materials?

Answer 2

Caterpillar tractors, scrapers & large hoes

Question 3

Why should water not be allowed to stand where foundations are to be placed?

Answer 3

It destabilizes and weakens the bearing capacity of soil

Question 4

If gravity drainage is not possible, how should rain and groundwater be controlled?

Answer 4

Using sump or wells

Question 5

What should be located before you dig?

Answer 5

Underground utilities such as gas, electricity and sewer.

Question 6

List 5 safety precautions to be used while working around excavation equipment.

Answer 6

1) Stay out of the circle
2) Stay well back from the rear
3) Don’t walk under boom

Question 7

Why are signs posted near a blast site?

Answer 7

So people are aware of the signals and warning procedures.

Question 8

What do 12 short whistle signals indicate?

Answer 8

Warning preceding a blast

Question 9

How long must a blaster wait before initiating the blast after the signal that warns of an impending blast?

Answer 9

Two minutes.

Question 10

What is an “All clear” sound signal used during blasting?

Answer 10

5 second whistle.

Question 11

What is used to prevent the public from falling in an open excavation?

Answer 11

Barricades and hoarding.

Question 12

How deep can excavations be before a ladder is required?

Answer 12

4 feet. (1.2 meters)

Question 13

What is the minimum width of walkways at excavations?

Answer 13

20 inches

Question 14

How is the width of a strip footing determined?

Answer 14

By the type of soil that supports the footing.

Question 15

When possible, should you save topsoil?

Answer 15

Can be re-used during landscaping

Question 16

What should be done before the excavation process?

Answer 16

Locate all services that are in the area of the excavation. Shut off, or isolate hazardous services

Question 17

Where do water services start from?

Answer 17

Enter below footings, below frost line, come up through basement floor close to a wall. Equipped with water meter.

Question 18

What pipes are connected to the storm sewer?

Answer 18

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.

Question 19

Can you put a gas line under the driveway?

Answer 19

Usually, yes you can but it is expensive to rip them up if a leak were to occur.

Question 19

Gas lines must be located, staked, installed and removed by:

Answer 19

Certified Gas Fitter

Question 19

How do you avoid gas leaks in a house?

Answer 19

The gas line must be outside of the building and topped by a meter.

Question 20

The electrical conduit must be about how far above the roof.

Answer 20

1220 MM so that no conductor is closer than 915 mm

Question 21

Electrical conductors must be no closer than:

Answer 21

4575 from the ground above vehicle areas and 3660 MM from the ground otherwise

Question 22

Service conductors are usually raised about:

Answer 22

5490 MM when accompanied by the telephone lines to avoid contact between them.

Question 23

Service conductors must be raised to:

Answer 23

5490 MM when accompanied by a telephone line.

Question 24

Underground electric services will be buried at

Answer 24

at least 610 mm deep, and 915 mm deep where it passes under an on-grade slab or driveway

Question 25

The Electrical meter must be installed how?

Answer 25

1525 to 1830 mm above finished grade, it is turned to face the exterior of the building

Question 26

How are telephone lines attached to the house?

Answer 26

Must be anchored to a mast on the fascia.

Question 27

How deep must the trench be for the telephone line?

Answer 27

460 MM deep

Question 28

What is one strategy to deal with water tables building up where foundations will bear?

Answer 28

Wells will be drilled and water will be pumped to maintain a low water table.

Question 29

How far must building excavations pile from edge? (NOT TRENCH)

Answer 29

4 feet minimum

Question 30

How far must excavation pile from edge of TRENCH?

Answer 30

2 feet minimum

Question 31

Who regulates the locations of service conduits?

Answer 31

BC Electrical Inspector

Question 32

Who is allowed to conduct blasting on job sites?

Answer 32

Only registered blasting contractors.