[Code of Federal Regulations]
[Title 29, Volume 8]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 29CFR1926.650]
[Page 366-368]
TITLE 29--LABOR
CHAPTER XVII--OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT
OF LABOR
PART 1926_SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION--Table of Contents
Subpart P_Excavations
Sec. 1926.650 Scope, application, and definitions applicable to this
Authority: Sec. 107, Contract Worker Hours and Safety Standards Act
(Construction Safety Act) (40 U.S.C. 333); Secs. 4, 6, 8, Occupational
Safety and Hea1th Act of 1970 (29 U.S.C. 653, 655, 657); Secretary of
Labor's Order No. 12-71 (36 FR 8754), 8-76 (41 FR 25059), or 9-83 (48 FR
35736), as applicable, and 29 CFR part 1911.
Source: 54 FR 45959, Oct. 31, 1989, unless otherwise noted.
subpart.
(a) Scope and application. This subpart applies to all open
excavations made in the earth's surface. Excavations are defined to
include trenches.
(b) Definitions applicable to this subpart.
Accepted engineering practices means those requirements which are
compatible with standards of practice required by a registered
professional engineer.
Aluminum Hydraulic Shoring means a pre-engineered shoring system
comprised of aluminum hydraulic cylinders (crossbraces) used in
conjunction with vertical rails (uprights) or horizontal rails (walers).
Such system is designed, specifically to support the sidewalls of an
excavation and prevent cave-ins.
Bell-bottom pier hole means a type of shaft or footing excavation,
the bottom of which is made larger than the cross section above to form
a belled shape.
Benching (Benching system) means a method of protecting employees
from cave-ins by excavating the sides of an excavation to form one or a
series of horizontal levels or steps, usually with vertical or near-
vertical surfaces between levels.
Cave-in means the separation of a mass of soil or rock material from
the side of an excavation, or the loss of soil from under a trench
shield or support system, and its sudden movement into the excavation,
either by falling or sliding, in sufficient quantity so that it could
entrap, bury, or otherwise injure and immobilize a person.
Competent person means one who is capable of identifying existing
and predictable hazards in the surroundings, or working conditions which
are unsanitary, hazardous, or dangerous to employees, and who has
authorization to take prompt corrective measures to eliminate them.
Cross braces mean the horizontal members of a shoring system
installed perpendicular to the sides of the excavation, the ends of
which bear against either uprights or wales.
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Excavation means any man-made cut, cavity, trench, or depression in
an earth surface, formed by earth removal.
Faces or sides means the vertical or inclined earth surfaces formed
as a result of excavation work.
Failure means the breakage, displacement, or permanent deformation
of a structural member or connection so as to reduce its structural
integrity and its supportive capabilities.
Hazardous atmosphere means an atmosphere which by reason of being
explosive, flammable, poisonous, corrosive, oxidizing, irritating,
oxygen deficient, toxic, or otherwise harmful, may cause death, illness,
or injury.
Kickout means the accidental release or failure of a cross brace.
Protective system means a method of protecting employees from cave-
ins, from material that could fall or roll from an excavation face or
into an excavation, or from the collapse of adjacent structures.
Protective systems include support systems, sloping and benching
systems, shield systems, and other systems that provide the necessary
protection.
Ramp means an inclined walking or working surface that is used to
gain access to one point from another, and is constructed from earth or
from structural materials such as steel or wood.
Registered Professional Engineer means a person who is registered as
a professional engineer in the state where the work is to be performed.
However, a professional engineer, registered in any state is deemed to
be a ``registered professional engineer'' within the meaning of this
standard when approving designs for ``manufactured protective systems''
or ``tabulated data'' to be used in interstate commerce.
Sheeting means the members of a shoring system that retain the earth
in position and in turn are supported by other members of the shoring
system.
Shield (Shield system) means a structure that is able to withstand
the forces imposed on it by a cave-in and thereby protect employees
within the structure. Shields can be permanent structures or can be
designed to be portable and moved along as work progresses.
Additionally, shields can be either premanufactured or job-built in
accordance with Sec. 1926.652 (c)(3) or (c)(4). Shields used in
trenches are usually referred to as ``trench boxes'' or ``trench
shields.''
Shoring (Shoring system) means a structure such as a metal
hydraulic, mechanical or timber shoring system that supports the sides
of an excavation and which is designed to prevent cave-ins.
Sides. See ``Faces.''
Sloping (Sloping system) means a method of protecting employees from
cave-ins by excavating to form sides of an excavation that are inclined
away from the excavation so as to prevent cave-ins. The angle of incline
required to prevent a cave-in varies with differences in such factors as
the soil type, environmental conditions of exposure, and application of
surcharge loads.
Stable rock means natural solid mineral material that can be
excavated with vertical sides and will remain intact while exposed.
Unstable rock is considered to be stable when the rock material on the
side or sides of the excavation is secured against caving-in or movement
by rock bolts or by another protective system that has been designed by
a registered professional engineer.
Structural ramp means a ramp built of steel or wood, usually used
for vehicle access. Ramps made of soil or rock are not considered
structural ramps.
Support system means a structure such as underpinning, bracing, or
shoring, which provides support to an adjacent structure, underground
installation, or the sides of an excavation.
Tabulated data means tables and charts approved by a registered
professional engineer and used to design and construct a protective
system.
Trench (Trench excavation) means a narrow excavation (in relation to
its length) made below the surface of the ground. In general, the depth
is greater than the width, but the width of a trench (measured at the
bottom) is not greater than 15 feet (4.6 m). If forms or other
structures are installed or constructed in an excavation so as to reduce
the dimension measured from the forms or structure to the side of the
excavation to 15 feet (4.6 m) or less
[[Page 368]]
(measured at the bottom of the excavation), the excavation is also
considered to be a trench.
Trench box. See ``Shield.''
Trench shield. See ``Shield.''
Uprights means the vertical members of a trench shoring system
placed in contact with the earth and usually positioned so that
individual members do not contact each other. Uprights placed so that
individual members are closely spaced, in contact with or interconnected
to each other, are often called ``sheeting.''
Wales means horizontal members of a shoring system placed parallel
to the excavation face whose sides bear against the vertical members of
the shoring system or earth.
