EXCAVATION

Question 1

Is any man-made cut, cavity or depression in any earth surface that is formed by earth removal.

Answer 1

Excavation

Question 2

Is a narrow excavation where the depth is greater than its width, and the width measured at the bottom is not greater than 15ft

Answer 2

Trench

Question 3

Hazards of excavation

Answer 3

Falls
Underground facilities
Vehicular Traffic
Confined Space Condition
Soil Collapse
Working Surface

Question 4

Principal Causes of Soil Collapse

Answer 4

Steep cutting angle
Superimposed load
Shock and Vibration
Water pressure
Drying

Question 5

2 types of Soil Collapse

Answer 5

Sliding
Toppling

Question 6

Most Stable:Clay

Answer 6

Type A

Question 7

Medium Stability:Silt and unstable rock

Answer 7

Type B

Question 8

Least stable:Grabel, Loamy Sand, Submerged Soil, soil from which water is freely seeping

Answer 8

Type C

Question 9

Slope of Type A

Answer 9

3/4:1 or 53

Question 10

Slope of Type B

Answer 10

1:1 or 45

Question 11

Slope of Type C

Answer 11

1 1/2:1 or 34

Question 12

Prevention of Soil Collapse

Answer 12

Shoring and Timbering
sheet Piles
Plate Lining System
Box Type
Shielding

Question 13

Walls of every excavation over __meter deep shall be supported by adequate shoring

Answer 13

1 meter

Question 14

In minimum berm, it should be not less than ___ of the depth of the excavation
May be reduced to not less than ___ provided that materials are stable, shoring and barriers are present

Answer 14

1/3
1meter

Question 15

Sloped Protected with sod, seed, shrubs or ground cover

Answer 15

Berm

Question 16

For falls, barricades of at least ___ high should be provided.

Answer 16

1 meter

Question 17

___ should be posted to prevent the public from going near the excavation

Answer 17

Signs

Question 18

In surface Crossing of trenches, what should be provided?

Answer 18

walkways and bridges

Question 19

In surface Crossings of Trenches a minimum clear width of ___ and standard___

Answer 19

20 inches, rails

Question 20

In surface crossing of trenches a minimum of __ past the surface edge

Answer 20

24inches

Question 21

In vehicular traffic provide workers with ____ or other suitable garments marked with reflectorized materials

Answer 21

warning vest

Question 22

Excavation shall be kept free of __ at all times

Answer 22

water

Question 23

Muddy area, workers should be provided with ___ to reduce the hazard of slipping

Answer 23

boots

Question 24

Hazardous atmosphere in confined space condition shows Oxygen

Answer 24

<19.5% or >23.5%

Question 25

Flammable gas concentration

Answer 25

> 10%

Question 26

In Ingress and Egress of a ladder a handhold of ___ should always be provided

Answer 26

0.75m

Question 28

Inspection of excavation is everywhen?

Answer 28

Daily before start of each shift
After heavy rain
Fissures tension cracks undercutting water seepage