MIOSHA: Summary: Part 9 Excavation, Trenching, and Shoring

Question 1

1. “Soil” means any of the following:

a. “Clay”–

Answer 1

a very fine textured soil that derives its resistance to displacement from cohesion and may be:

Question 2

1. “Soil” means any of the following:

“Soft clay”–

Answer 2

a clay-type soil that has an unconfined strength of less than 1.0 ton per square foot.

Question 3

1. “Soil” means any of the following:

“Medium clay,”

Answer 3

sometimes called plastic–a clay-type soil that has a minimum unconfined strength of 1.0 ton per square foot.

Question 4

1. “Soil” means any of the following:

“Firm soil”–

Answer 4

a clay-type soil that is resistant to forces causing rupture or displacement. A firm clay has a minimum unconfined strength of 1.5 tons_ per square foot.

Question 5

1. “Soil” means any of the following:

“Stiff clay”–

Answer 5

a clay-type soil that is very resistant to forces causing rupture or displacement. A stiff clay has a minimum unconfined strength of 2.5 tons_ per square foot.

Question 6

1. “Soil” means any of the following:

“Fill”–

Answer 6

a manmade soil condition that may be constructed of any type of soil or combination thereof.

Question 7

1. “Soil” means any of the following:

“Granular soil”–

Answer 7

a coarse grained soil that does not possess cohesion but derives its strength from internal friction.

Question 8

1. “Soil” means any of the following:

Organic soil”–

Answer 8

a soil that contains significant amounts of peat, muck, or marl.

Question 9

1. “Soil” means any of the following:

“Running soil”–

Answer 9

any type of soil that has insufficient strength to stand unsupported. Running soil tends to run or slough into the excavation as the excavation is being dug.

Question 10

1. “Soil” means any of the following:

Toe of slope” means

Answer 10

the point at which the side of an

excavation intersects the lowest level of the excavation

Question 11

B. Locating utility lines

An employer shall not excavate in a street, highway, public place, a private easement of a public utility, or near the location of a public utility facility owned, maintained, or installed on a customer’s premises, without X

Answer 11

having first ascertained the location of all underground facilities of a public utility in the
proposed area of excavation

Question 12

B. Locating utility lines

Upon receiving X, an
employer shall exercise reasonable care when working in close proximity to the underground facilities of any public utility. If the facilities are to be exposed, or are likely to be exposed; only X shall be employed in such circumstances.

Answer 12

the information from the public utility

hand digging

Question 13

C. Excavation; consideration of soil types; water; slide
hazards:

If different textured soils are encountered in the side of an excavation, each X, except that the slope shall not Y

Answer 13

soil type of the excavation shall be cut to the proper angle of repose

steepen between the toe of the slope and the ground level where soft clay or running soil is encountered in the lower cut.

Question 14

C. Excavation; consideration of soil types; water; slide
hazards:

If the excavation is a trench, a X shall be used or the sides shall be properly sloped to protect against a cave-in.

Answer 14

trench shoring system

Question 15

C. Excavation; consideration of soil types; water; slide
hazards:

An employee shall not work in an excavation in which there is accumulated water or in which water is accumulating unless X. The X adequately vary with each situation, but may include special support or shield systems to protect from cave-ins, water removal to control the level of accumulating water, or the use of a safety harness and lifeline.

Answer 15

precautions have been taken to protect employees against the hazards posed by water accumulation

Question 16

C. Excavation; consideration of soil types; water; slide
hazards:

If water is controlled or prevented from accumulating by the use of water removal equipment, the water removal
equipment and operation shall be X

Answer 16

monitored by a qualified employee to ensure that the equipment is properly operated.

Question 17

C. Excavation; consideration of soil types; water; slide
hazards:

An ongoing X of an excavation or trench shall
be made by a qualified person. After every Y, an inspection shall be made by a qualified employee for evidence of possible slides or cave-ins. Where these conditions are found, all work shall Z

Answer 17

inspection

rainstorm or other hazard-producing occurrence

cease until additional precautions, such as additional shoring or reducing the slope, have been accomplished.

Question 18

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

A tree, boulder, rock fragments, or other obstructions whose movement could cause injury to an employee shall be X

Answer 18

removed or supported.

Question 19

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

An excavation that an employee is required to enter shall have excavated and other material stored and retained not less than X feet from the excavation edge.

Answer 19

2

Question 20

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

When a shoring system is used, the system shall be designed and used to X when heavy equipment, material handling equipment, or material is located near an excavation.

Answer 20

resist the added pressure

Question 21

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

When mobile equipment is utilized or permitted adjacent to an excavation where the operator’s vision is restricted, X shall be utilized or a signal person shall be used.

Answer 21

stop logs or barricades

Question 22

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

An excavation X or more inches in depth and occupied
by an employee shall be provided with either a ladder
extending not less than Y feet above the top as a
means of access or with a ramp meeting the requirements of subrule (6) of this rule. Lateral travel along the wall of a trench to a ladder or other means of egress shall not exceed Z feet.

Answer 22

48

3

25

Question 23

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

An earth ramp may be used in place of a ladder if it meets all of the following requirements:

a. The ramp material shall be X.

Answer 23

stable

Question 24

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

An earth ramp may be used in place of a ladder if it meets all of the following requirements:

b. The sides of the excavation above the ramp shall be
X or sheeted or Y

Answer 24

maintained to the angle of repose

shored along the means of egress.

Question 25

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

An earth ramp may be used in place of a ladder if it meets all of the following requirements:

c. The degree of angle of the ramp shall not be more than X

Answer 25

45 degrees.

Question 26

D. Excavation; obstructions; retaining materials; egress;
guarding; heavy equipment

An earth ramp may be used in place of a ladder if it meets all of the following requirements:

d. Vertical height between the floor of the trench and the toe of the ramp shall not exceed X inches

Answer 26

30

Question 27

E. Excavation; angle of repose

1. The side of an excavation more than X feet deep shall
   be Y as prescribed in table 1, unless supported as
   prescribed in this part.

Answer 27

5

sloped

Question 28

E. Excavation; angle of repose

2. An excavation less than X feet in depth shall also be
   Y when examination of the ground indicates hazardous earth movement may be expected.

Answer 28

5

effectively protected

Question 29

E. Excavation; angle of repose

3. If 1 side of a trench is X feet or less in depth and the other side is deeper than X feet, the side Y shall be protected as provided in this part. All excavated material shall be placed on the low side if possible.

Answer 29

5
5
deeper than 5 feet

Question 30

E. Excavation; angle of repose

Special attention shall be given to a side that X

Answer 30

may be

adversely affected by weather or moisture content.

Question 31

F. Supporting systems; angle of repose; tie backs;
tight sheeting; additional bracing

The angle of repose and the design of the supporting
system for a side of an excavation shall be based on the
valuation of all of the following factors:
Depth of cut and type of soil:

a. Possible variation in the X of the material
while the excavation is open

Answer 31

water content

Question 32

F. Supporting systems; angle of repose; tie backs;
tight sheeting; additional bracing

The angle of repose and the design of the supporting
system for a side of an excavation shall be based on the
valuation of all of the following factors:
Depth of cut and type of soil:

b. Anticipated changes in the material due to X

Answer 32

exposure to air, sun, water, or freezing

Question 33

F. Supporting systems; angle of repose; tie backs;
tight sheeting; additional bracing

The angle of repose and the design of the supporting
system for a side of an excavation shall be based on the
valuation of all of the following factors:
Depth of cut and type of soil:

c. Load imposed by X

Answer 33

structures, equipment, overlying

material, or stored material

Question 34

F. Supporting systems; angle of repose; tie backs;
tight sheeting; additional bracing

The angle of repose and the design of the supporting
system for a side of an excavation shall be based on the
valuation of all of the following factors:
Depth of cut and type of soil:

e. Vibration from X

Answer 34

traffic, equipment, or blasting.

Question 35

F. Supporting systems; angle of repose; tie backs;
tight sheeting; additional bracing

2. A support system shall be designed by X. The design of the supporting system shall be maintained at Y. Changes from the design of the support system shall be approved by X

Answer 35

a qualified employee

the jobsite

a qualified employee.

Question 36

Utility locates marked in orange are ____________.

Answer 36

communication fiber optics

Question 37

As a general rule, utility locates may be within _____ variance.

Answer 37

a 18-in

Question 38

_________ is hand digging in compacted soils to expose underground pipe and lines.

Answer 38

potholing