The purpose of this standard is to define minimum requirements for prevention of
hazards associated with excavation.
This standard applies to all excavation activ ities carried out within SABIC and it’s
3.1 Angle of Repose: The angle with the horizontal at which a particular earth
material will stand indefinitely without movement.
3.2 Excavation: Any work that requires breaking the earth’s surface or pavement
including the removal of previously installed roadways, slabs or foundations at
or below the surrounding ground level.
3.3 Hand Excavation: Any excavation that uses only hand tools for breaking and
removing earth’s surface. A typical hand tool used for hand excavation is a
shovel. Hand excavation is carried out in congested areas or to protect
underground pipes, cable, etc.
3.4 Machine Excavation: Any excavation which uses machines for breaking hard
surfaces like concrete or asphalt areas e.g., jack hammer, concrete cutters,
hydraulic or pneumatic tools, etc., or removing earth’s surface e.g., back-hoe,
etc. Machine excavation is used for large trench excavation or plant areas in
safe locations free from underground installations.
3.5 Sides, Walls or Faces: The vertical or inclined earth surfaces formed as a
result of excavation work.
3.6 Shall: Signifies mandatory requirements.
3.7 Shoring: A system of braces, uprights (ply wood or steel) and walls to protect
people and the adjacent structures foundations in an excavation or trench
from the collapse of the adjacent unstable soil.
3.8 Should: Signifies recommended/optional requirements.
3.9 Trench: A narrow excavation below the surface of the ground. In general, the
depth is greater than the width but the width of a trench is not greater than
July 2001 SABIC Safety S tandard SF – 134 : P age 1 of 5
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3.10 Trench Shield: A shoring system composed of steel plates and bracing,
welded or bolted together, which support the walls of a trench from the
ground level to the bottom of the trench and can be moved along as the work
SABIC and its Affiliates shall develop procedures and programs that meets the
following requirements on excavation:
SABIC Industrial Security shall be consulted for any clarification to this standard.
The clarification given by SABIC Industrial Security shall be complied with and
4.1 Appropriate work permit shall be obtained for excavation work.
4.2 Following shall be considered prior to the issue of a work permit for
4.2.1 Determination of the presence and locations of underground fuel,
chemical or utility pipes; electrical, telephone, instrument wires, or
cables with reference to up-to-date underground services drawings of
area to be excavated.
4.2.2 Use of a cable locator or other techniques such as exploratory
excavation to identify location of underground services.
4.2.3 Identification of location of underground serv ices by erecting
indicators, markers, or locators.
4.2.4 If possible de-energize and/or isolation of the underground services
for excavation. If the underground utilities cannot be de-energized or
the location is not definite, then the method of excavation shall be
established to minimize hazards by such means as:
Trail pit by hand excavation along the area to be excavated.
Use of hand-tools in area of underground services.
Insulate men and equipment from possible electrical contact.
Use tools or equipment that will reduce possibility of damage to
underground services and hazard to worker.
4.2.5 Preparation of drawings and sketches, highlighting clearly the area
and depth of excavation.
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4.2.6 Defining the type of excavation, manual and/or machine excavation.
4.2.7 Excavations in excess of 3 meters, adjacent to structures, subject to
vibration or ground water shall require a plan provided by a Civ il
Engineer and approved by the Engineering Department Head.
Calculations in support for the shoring type/method shall be
submitted for review and approval of the plan.
4.2.8 Determination shall be made whether gas tests are necessary and at
which stage of excavation they will be necessary.
4.2.9 Inspection of work area with the work crew supervisor or the scope
of excavation should be clearly defined.
4.2.10 Notification to all concerned if the excavation will obstruct any
roadway or access either partially or totally.
4.2.11 Marking out on the ground the exact location and area of the
excavation. This should be done with chalk or paint marking and not
with pegs or pins.
4.2.12 Communicating to the work crew on the proper procedure and
hazards involved in excavation. The work scope shall be clearly
defined and communicated.
4.3 Personnel shall not enter or perform work in an excavation which requires
their head to be below the surface of the ground until:
4.3.1 Satisfactory gas and oxygen tests have been secured.
4.3.2 A ladder or stairway has been provided for safe entrance and exit.
4.3.3 Adequate shoring or sloping of the trench wall has been provided if
the depth exceeds 1.5 meters.
4.3.4 Adequate provision to dewater the ground water is made.
4.4 Excavation more than 1.2 meters deep shall be treated as work requiring a
confined space entry permit.
4.5 Excavation work shall be suspended if any unusual conditions are found or
unidentified or unexpected pipe, cable, concrete or other obstructions are
uncovered or Permit conditions are not implemented.
4.6 Excavations shall be inspected daily by the person responsible for the
excavation. If evidence of possible cave-ins or slides is apparent, all work in
the excavation shall cease until the necessary precautions have been taken
to safeguard the employees.
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4.7 If the presence of any underground services is indicated, the underground
services shall be exposed and exactly located by hand tool excavation.
4.8 Whenever a manual exploration is made as a requirement to identify any
underground obstacle before a machine excavation, it should be clearly
specified on the permit that all the obstructions shall be physically located
before starting with any machine excavation.
4.9 All trench (vertical sides) excavations greater than 1.5 meters in depth shall
be shored or sloped to avoid collapse.
4.10 No mechanical excavation shall be made within 1 meter of any underground
4.11 Any excavation more than 1 meter deep shall be gas-tested prior to the start
of each day or shift. The issuer of the work permit may, if the conditions
warrant, require more frequent testing or continuous monitoring.
4.12 Excavated materials or mechanical equipment should not be placed within 1
meter of the edge of any excavation. For excavations up to 1.2 meters deep,
equipment and other heavy objects must be kept at least 2 meters from the
edge of the excavation. For excavations in excess of 1.2 meters, or when it
is necessary to operate heavy equipment from nearer than 2 meters from
the edge, sheet piling, shoring, and bracing shall be prov ided.
4.13 Ladders or other suitable means of access/egress to excavations shall be
provided at a maximum spacing of 30 meters on the perimeter of open
excavations and 7.5 meters for trench excavations greater than 1.2 meters
4.14 Appropriate permit shall be obtained for entry of motor-driven excavation
equipment into hazardous area.
4.15 Load carrying capacity of soil shall be established for safe use of mobile
industrial equipment in or near excavation. Suitable protection against
collapse of soil shall be provided by use of mats, barricades, restricting the
location of equipment, or shoring.
4.16 Location of all known underground services shall be physically located before
permitting any machine excavation.
4.17 Red concrete shall not be cut as the red color concrete is used to mark
underground electrical systems.
4.18 Power/Machine excavation is not permitted in areas where underground
electrical system exists.
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4.19 Excavation shall be inspected periodically for presence of groundwater,
change in soil condition and effects of weather such as rain or wind. Safe
means of continuing the work shall be established as any condition changes.
4.20 If gas, toxic or flammable materials are encountered, appropriate tests shall
be made to establish the need for respiratory equipment, ventilation or other
measures required to continue the excavation safely.
4.21 All exposed cable and pipes should be adequately supported.
4.22 Barricades shall be placed around all excavations and flashing lights shall be
installed at night if the excavation is not in a well-lit area.
4.23 Excavations, regardless of their depth, shall not be left unattended without
steps being taken to prevent someone from inadvertently tripping, falling or
driving in it.
4.24 Adequate means of dewatering excavations shall be provided as required.
4.25 A signal-person should be prov ided to coordinate powered equipment work
4.26 Walkways or bridges shall be prov ided with standard handrails where
employees or equipment are required or permitted to cross over excavations.
4.27 Shoring and/or Sloping
4.27.1 Where employees are exposed to walls and faces of excavations and
trenches 1.2 meters or more in depth, the walls and faces shall be
sloped to their angle of repose or shoring installed.
4.27.2 In no case shall the slope of the angle be greater than 45 degrees.
When material such as silt or sand is encountered or when erosion or
slide planes appear, the slope should be flattened.
4.27.3 Bracing and shoring of trenches shall be carried down and along with
the hand excavation. Shoring shall be installed prior to personnel
entering a machine-excavated trench.
4.28 At the conclusion of the excavation work:
4.28.1 Backfilled excavations shall be compacted to substantiate the load
bearing capability of the surrounding area before the barricades are
4.28.2 All newly installed items below grade shall be entered into
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