California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 4 - Construction Safety Orders › Article 6 - Excavations › Section 1540 - Excavations

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) Scope and
					 application. This article applies to all open excavations made in the earth's
					 surface. Excavations are defined to include trenches.
(b) Definitions applicable to this article.
Accepted engineering practices means those requirements
						which are compatible with standards of practice required by a registered
						professional engineer.
Aluminum hydraulic shoring. 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. 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). 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. 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.
Crossbraces. 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.
Excavation. Any man-made cut, cavity, trench, or
						depression in an earth surface, formed by earth removal.
Faces or sides. The vertical or inclined earth surfaces
						formed as a result of excavation work.
Failure. 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. 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. The accidental release or failure of a cross
						brace.
Protective system. 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. 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. 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. 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). 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 Section
						1541.1(c)(3) or
						(c)(4). Shields used in trenches are usually
						referred to as "trench boxes" or "trench shields."
Shoring (Shoring system). 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). A method of protecting
						employees from cave-ins by excavating to form sides of an excavation that are
						inclined away form 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. 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. 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. 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. Tables and charts approved by a
						registered professional engineer and used to design and construct a protective
						system.
Trench (Trench excavation). 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. 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 or less, (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. 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. 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.
1.
						Repealer and new section filed 8-23-82; effective thirtieth day thereafter
						(Register 82, No. 35). For prior history, see Register 75, No.
						21.
2. Amendment of subsection (b)(3) filed 11-18-83; effective
						thirtieth day thereafter (Register 83, No. 47).
3. Amendment of
						subsections (b)(2) and (b)(3) filed 5-1-87; operative 5-31-87 (Register 87, No.
						19).
4. Repealer and new section filed 8-26-91; operative 9-25-91
						(Register 92, No. 13).
5. Editorial correction of subsection (b) --
						"Cave-in" (Register 2016, No. 35).
Note: Authority cited: Section
						  142.3, Labor
						  Code. Reference: Section
						  142.3, Labor
						  Code.