A dog digging on a beach. Digging, also referred to as excavation, is the process of using some implement such as claws, hands, manual tools

For other uses, see Digging (disambiguation) and Dig (disambiguation).

Movements of the ploughman when digging

A dog digging on a beach.
Digging, also referred to as excavation, is the process of using some implement such as claws, hands, manual tools or heavy equipment, to remove material from a solid surface, usually soil, sand or rock on the surface of Earth. Digging is actually the combination of two processes, the first being the breaking or cutting of the surface, and the second being the removal and relocation of the material found there.[1] In a simple digging situation, this may be accomplished in a single motion, with the digging implement being used to break the surface and immediately fling the material away from the hole or other structure being dug.

Many kinds of animals engage in digging, either as part of burrowing behavior or to search for food or water under the surface of the ground.[2] Historically, humans have engaged in digging for both of these reasons, and for a variety of additional reasons, such as engaging in agriculture and gardening, searching for minerals, metals, and other raw materials such as during mining and quarrying, preparing for construction, making fortifications and irrigation, and also excavations in archaeology, searching for fossils and rocks in palaeontology and geology and burial of the dead.

Digging by humans

Twelfth century illustration of a man digging.
Reasons

A group of men digging for Kauri gum in New Zealand.
There are a wide variety of reasons for which humans dig holes, trenches, and other subsurface structures. It has long been observed that humans have a seemingly instinctive desire to dig holes in the ground, manifesting in childhood.[3]

Like other animals, humans dig in the ground to find food and water. Wood-lined water wells are known from the early Neolithic Linear Pottery culture, for example in Kückhoven (an outlying centre of Erkelenz), dated 5090 BC and Eythra, dated 5200 BC in Schletz (an outlying centre of Asparn an der Zaya) in Austria.[4] Humans are unique among animals in the practice of burial of the dead. Intentional burial, particularly with grave goods, may be one of the earliest detectable forms of religious practice since, as Philip Lieberman suggests, it may signify a "concern for the dead that transcends daily life".[5] Evidence suggests that the Neanderthals were the first human species to practice burial behavior and intentionally bury their dead, doing so in shallow graves along with stone tools and animal bones.[6][7] Exemplary sites include Shanidar in Iraq, Kebara Cave in Israel and Krapina in Croatia. Some scholars, however, argue that these bodies may have been disposed of for secular reasons.[8] Notably, burial of the dead prevents diseases associated with the presence of corpses, and prevents scavengers and other predators from being attracted.

The earliest undisputed human burial discovered so far dates back 100,000 years. Human skeletal remains

1. Excavation Safety

2. 2
Excavations

3. 3
Injury and Death
•Excavating is one of the
most hazardous
construction operations
•Most accidents occur in
trenches 5-15 feet deep
•There is usually no warning
before a cave-in

4. 4
Excavation Hazards
Excavation Cave-ins are the
greatest risk
Other hazards include:
•Asphyxiation due to lack of
oxygen
•Inhalation of toxic materials
•Fire
•Moving machinery near the
edge of the excavation can
cause a collapse
•Accidental breaking of
underground utility lines

5. 5
Definitions
•Excavation–a man-made cut, cavity, trench, or
depression formed by earth removal
•Trench–a narrow excavation. The depth is
greater than the width, but not wider than 4 meters
•Shield-a structure able to withstand a cave-in
and protect employees
•Shoring-a structure that supports the sides of an
excavation and protects against cave-ins
•Sloping-a technique that employs a specific
angle of incline on the sides of the excavation.
The angle varies based on assessment of
impacting site factors.

6. 6
•The risk of working in excavation
•How to protect employees from cave-ins
•Factors that pose a hazard to employees
working in excavations
•The role of a competent person in
excavation site
Focus of Training

7. 7
Protection of Employees
Employees should be protected from
cave-ins by using an adequately designed
protective system
Protective systems must be able to resist all
expected loads to the system

8. 8
Requirements for Protective Systems
A well-designed protective system
•Correct design of sloping and benching systems
•Correct design of support systems, shield systems,
and other protective systems
Plus
Appropriate handling of materials and equipment
Plus
Attention to correct installation and removal
EqualsProtection of employees at excavations

9. 9
Design of Protective Systems
The employer shall select and construct :
•slopes and configurations of sloping and
benching systems
•support systems, shield systems, and other
protective systems
•Shield-can be permanent or portable. Also
known as trench box or trench shield
•Shoring-such as metal hydraulic, mechanical or
timber shoring system that supports the sides
•Sloping-form sides of an excavation that are
inclined away from the excavation

10. 10
Protect Employees Exposed to
Potential Cave-ins
⚫Slope or bench the sides
of the excavation,
⚫Support the sides of the
excavation, or
⚫Place a shield between the
side of the excavation and
the work area

11. 11
Cave-in Hazard
This excavation has
inadequate support
posts and egress &
access
Inadequate protective
system

12. 12
Inadequate Protective System
This worker is in a
trench with no
protective system, that
is not sloped or
benched and has no
means of egress

13. 13
Factors Involved in Designing a
Protective System
⚫Soil classification
⚫Depth of cut
⚫Water content of soil
⚫Changes due to
weather and climate
⚫Other operations in the
vicinity

14. 14
Shoring
General
•Provides a framework to work in
•Uses wales, cross braces and uprights
•Supports excavation walls
•Must know soil type
•Must know depth and width of excavation

15. 15
Sloping & Benching
The design of protection systems, including sloping,
benching, shoring and shielding, will depend primarily
on two factors:
⚫The types of soil encountered, and in the depth of the
excavations
⚫Persons working in excavations can be protected by
sloping and benching the sides of the excavation in
accordance with the industrial safety and Health Law

16. 16
Sloping & Benching
Type Slope maximum
degree
Soil Wet soil 1 : 1 ~ 1 : 1.5 45°~ 34°
Dry soil 1 : 0.5 ~ 1 : 163°~ 45°
Rock Weathered
rock
1 : 0.8 51°
Loose rock 1 : 0.5 63°
Stable rock 1 : 0.3 73°

17. 17
Trench Shield
A trench shield
was built around
this work area

18. 18
Hydraulic Trench Support
•Using hydraulic jacks the
operator can easily drop
the system into the hole
•Once in place, hydraulic
pressure is increased to
keep the forms in place
•Trench pins are installed
in case of hydraulic failure

19. 19
Materials and Equipment
•Equipment used for
protective systems must
not have damage or
defects that impair
function.
•If equipment is damaged,
the competent person
must examine it to see if it
is suitable for continued
use.
•If not suitable,remove it
from service until a
professional engineer
approves it for use.

20. 20
Protection from Vehicles
•Install barricades
•Hand/mechanical signals
•Stop logs
•Grade soil away from
excavation
•Fence or barricade
trenches left overnight

21. 21
Hazardous Conditions
The weight and
vibrations of the crane
make this a very
hazardous condition.
They should not be
working under this
crane.

22. 22
Spoils
•Don’t placespoil soil within 1
meter from edge of
excavation
•Rocks, stones or other
debris will not be left any
closer than 2 meters to the
edge of the excavation
•Measure from nearest part of
the spoil to the excavation
edge
•Place spoils so rainwater
runs away from the
excavation
•Place spoil well away from
the excavation

23. 23
•Water accumulation
•Oxygen deficiency
•Toxic fumes
•Access/Egress
•Falls
•Mobile equipment
Other Excavation Hazards

24. 24
Water is Hazardous
When water is
present in an
excavation, it is
extremely
hazardous to enter
Note that these
workers are not
wearing hardhats to
protect them from
materials falling into
the trench

25. 25
Water = Cave-in Hazard
These workers must
be protected from
cave-in. Note the
water in the bottom of
the trench. This is a
very hazardous
condition!

26. 26
Hazardous Atmosphere
Test excavations more than
before an employee enters
the excavation for:
•Oxygen deficiency
•High combustible gas
concentration
•High levels of other
hazardous
substances

27. 27
Means of Egress
A stairway, ladder,
or ramp must be
present in
excavations that
are 4 or more feet
deep, and within
25 feet of the
employees
This ladder does not meet the
requirements of the standard
The ladder should extend 3 feet
above the excavation

28. 28
These two ladders which
are lashed together are
not an adequate means
of egress
The ladder should
extend 3 feet above the
top of the excavation
Hanging electrical
cables touching the
aluminum ladder
Access and Egress

29. 29
Protection from Falls, Falling
Loads, and Mobile Equipment
•Install barricades
•Use hand / mechanical signals
•Grade soil away from excavation
•Fence or barricade trenches left overnight
•Use a flag man when signs, signals and barricades are not
enough protection
⚫All heavy equipments (e.g. compressor units, generators, etc.)
shall be kept minimum of 2 meters away from the edge
⚫Wheel locks are to be placed on any wheeled vehicle, which
is parked, in close proximity to an excavation.
⚫Heavy vehicular traffic shall not be permitted near un-shored
sides
⚫Location of underground utilities

30. 30
Competent Person
Must have had specific
training in and be
knowledgeable about:
•Soils classification
•The use of protective
systems
•The requirements of the
standard
Must be capable of identifying
hazards, and authorized to
immediately eliminate hazards

31. 31
Inspections of Excavations
A competent person must
make daily inspections of
excavations, areas around
them and protective systems:
•Before work starts and as
needed,
•After rainstorms, high winds
or other occurrence which
may increase hazards, and
•When you can reasonably
anticipate an employee will
be exposed to hazards.

32. 32
Inspections of Excavations
If the competent person finds
evidence of a possible cave-in,
indications of failure of
protective systems, hazardous
atmospheres, or other
hazardous conditions:
•Exposed employees must
be removed from the
hazardous area
•Employees may not return
until the necessary
precautions have been
taken

33. 33
Site Evaluation Planning
Before beginning excavation:
•Evaluate soil conditions
•Construct protective
systems
•Test for low oxygen,
hazardous fumes and toxic
gases
•Provide safe in and out
access
•Contact utilities
•Determine the safety
equipment needed
Fissure

34. 34
•The greatest risk in an excavation is a cave-in.
•Employees can be protected through sloping,
shielding, and shoring the excavation.
•A competent person is responsible to inspect
the excavation.
•Other excavation hazards include water
accumulation, oxygen deficiency, toxic fumes,
falls, and mobile equipment.
Summary