OSHA 30 Construction Excavations Part 1,2,3 Flashcards

1
Q

what is a trench

A

a hole that is deeper then it is wide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the OSHA requirements for trenches supports

A

the trench must be 5 feet deep and their must be reasonable evidence that their is a cave-in possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

OSHA requires air monitoring in trenches deeper

A

4 feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

can you tell a ground is type A soil type by look

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are characterisitcs in a cavein in

A

lateral PRESSURE up to 800LBS

Cubic yard weight can be 3000lbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how far away can spoil pile be

A

2 feet from side of trench

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the 4 classification soil

A

solid rock

type A

Type B

Type C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are common soil tests

A

ribbon
thread
thumb
dry strength
sedimentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

type B soil is not

A

sand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

when are protective systems not needed

A

when working with solid rock

when dealing with trenches 5 feet or less and without sign of possible cave-ins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

type A protective systems

A

sloping 3/4 of an inch every 1 foot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

type B protective systems

A

having slopping at 45 degrees or 1 foot per 1 foot of trench wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why type c soil not practicel

A

it is a poor conditions for it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what must be done if type C soil is sloped

A

it needs to be 1.5 per 1 foot of trench

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

should trenches that are supported by aluminum shoring be allowed to be entered after they are placed

A

no`

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how far away should the shoring of the hydraulic shores be

A

they should e be 4 feet max away from each other and the lowest cylinders should be two feet min from the ground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

most shores are pumped up to

A

1000lbs and imparts 3000psi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what needed for workers to work in a type C -type soil

A

whalers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

type B soil allows for how many options of protection

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what type of soil is the most common

A

type B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

mixed oak timber have greater bending strength then Douglas fir per square inch

A

false

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

were are the systems for working workers placed in

A

in section E 1926

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are screw jack systems

A

they are like hydraulics but must be adjusted manually

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When must an engineer be involved in shoring techniques

A

when the excavation is deep the 20 feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how far away must equipment be from power sources

A

10 feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what zone but all equipment be operated in

A

the zone full operation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

were can the osha excavation standard be found

A

29CFR excavation standard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is the requirement of a competent worker

A

someone who know

General protection requirements

Soil classifications

protective systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is required for testing soil

A

at least on qualitative and one quantitative test

30
Q

What is the most trusted classification system for examining soil

A

the OSHA system

31
Q

how authorizes the competent person

A

the person’s employer

32
Q

cemented soil

A

soil that cannot be turned to powder simply with hand pressure

33
Q

cohesive soil

A

high clay content soil

hard to break when dry

plastic when moist

does not crumble

34
Q

dry soil

A

shows no visible signs of moisture

35
Q

fissured

A

soil with a tendency to break along definite plans of fracture

36
Q

granular soil

A

gravel, sand, silt

no cohesive strength

no or little clay

37
Q

layered system

A

2 or more soil or rock types

38
Q

plastic soil

A

can be molded without cracking

39
Q

stable rock

A

a rock that can be excavated with vertical sides and remain intact

40
Q

tension cracks

A

form at a horizontal distance of 0,5 to 0.75 times the depths of the trench measure from the top of the vertical face of the trench
ex 10 foot deep trench crack 5 to 7.5 feet back from top of trench

41
Q

sludding or sluffing results from

A

tension cracks

42
Q

When does toppling occur

A

when the vertical face shears along the tension crack line an topples into the excavation

43
Q

subsidence/bulging

A

an unsupported excavation creating an unbalanced stress

44
Q

heaving/ squeezin

A

caused by downward pressure from weight of adjoining soil
causing bulging of the cut

45
Q

boiling

A

seen from an upward water flow into the bottom of the cuy

46
Q

surcharge loads

A

any increase in weight in the adjacent area next to the cut

47
Q

ground or rain water in a layered system will produce

A

a spring or flow between the layers and into the excavation

48
Q

is it problematic when the layers slope

A

yes

49
Q

confined compressive strength

A

the load per unit are at which soul will fail

50
Q

unit weight of soil

A

weight of one unit of particular soil

51
Q

is solid rock allowed to be 90degree if less then 20 ft deep

A

yes

52
Q

type a soil

A

must be clay

most contain moist

must be able to withstand 1.5 tons of cubic pressure

53
Q

common example so f type A soil

A

clay, silty clay, sandy clay, and clay loam.

54
Q

when is soil not type A

A

if it is cracked / fissured
if it is subject to vibrations
if the layers dip into the excavation
has been previously disturbed
heavy loads are found along the edge

55
Q

What are the properties of type B soil

A

soil that can withstand strength of .5 to 1.5 Tsf

granular cohesions less including

silt
sandy load
silty clay loom and sandy clay loom

56
Q

type Be can be dry rocks but if they are

A

not stable

57
Q

type C soil characteristics

A

soil rated below 0.5 tsf or

granule soil such as gravel, sand , loamy sand or submerged rock that is unstable

58
Q

when is layered systems materials open to mixig with eachother

A

when the layered systems soils are 4Horizontal:1Vertical

59
Q

what can a visual test help find

A

whether a soul is cohesive

whether it is made of of granular material

60
Q

soil testing is never done from

A

inside the cut

61
Q

how should you roll soil in a manual test

A

it should be 1/8 inch diameter by 2 inches

62
Q

if the excavation being done is temporary and is less then 12 feet how large can the slope be

A

1/2 by 1

63
Q

Excavation options for type A soil

A

B-1.1 Excavations made in Type A soil.

  1. All simple slope excavation 20 feet or less in depth shall have a maximum allowable slope of ¾:1.

Simple Slope – General

SIMPLE SLOPE–GENERAL

Exception: Simple slope excavations which are open 24 hours or less (short term) and which are 12 feet or less in depth shall have a maximum allowable slope of ½:1.

Simple Slope – Short Term

SIMPLE SLOPE–SHORT TERM

  1. All benched excavations 20 feet or less in depth shall have a maximum allowable slope of 3/4 to 1 and maximum bench dimensions as follows:Simple Bench

SIMPLE BENCH

Multiple Bench

MULTIPLE BENCH

  1. All excavations 8 feet or less in depth which have unsupported vertically sided lower portions shall have a maximum vertical side of 3½ feet.

Unsupported Vertically Sided Lower Portion – Maximum 8 Feet In Depth

UNSUPPORTED VERTICALLY SIDED LOWER PORTION–MAXIMUM 8 FEET IN DEPTH

All excavations more than 8 feet but not more than 12 feet in depth with unsupported vertically sided lower portions shall have a maximum allowable slope of 1:1 and a maximum vertical side of 3½ feet.

Unsupported Vertically Sided Lower Portion – Maximum 12 Feet In Depth

UNSUPPORTED VERTICALLY SIDED LOWER PORTION–MAXIMUM 12 FEET IN DEPTH

All excavations 20 feet or less in depth which have vertically sided lower portions that are supported or shielded shall have a maximum allowable slope of ¾:1. The support or shield system must extend at least 18 inches above the top of the vertical side.

Supported Or Shielded Vertically Sided Lower Portion

SUPPORTED OR SHIELDED VERTICALLY SIDED LOWER PORTION

  1. All other simple slope, compound slope, and vertically sided lower portion excavations shall be in accordance with the other options permitted under § 1926.652(b)
64
Q

Excavation types for type B soil

A
  1. All simple slope excavations 20 feet or less in depth shall have a maximum allowable slope of 1:1.

Simple Slope

SIMPLE SLOPE

  1. All benched excavations 20 feet or less in depth shall have a maximum allowable slope of 1:1 and maximum bench dimensions as follows:

Single Bench

SINGLE BENCH

Multiple Bench

MULTIPLE BENCH

  1. All excavations 20 feet or less in depth which have vertically sided lower portions shall be shielded or supported to a height at least 18 inches above the top of the vertical side. All such excavations shall have a maximum allowable slope of 1:1.

Vertically Sided Lower Portion

VERTICALLY SIDED LOWER PORTION

  1. All other sloped excavations shall be in accordance with the other options permitted in § 1926.652(b).
65
Q

shoring

A

any mechanical system used to prevent collapse og an excavation

66
Q

what OSHA standards outline the requirements of shoring

A

appendix C and D

67
Q

What is the only type of soil that will never need whaling

A

type A soil

68
Q

vertical shores are use their must be a min of

A

3 shores

69
Q

aluminum shores are usual installed

A

vertically

70
Q

earth excavation is below a shield is permitted as long as it is less then

A

2feet