does a trench box have to be level with the ground?

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## 29 CFR 1926 (OSHA) ## Subpart P-Excavations 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 [redacted postal code]), or 9-83 (48 FR [redacted postal code]), as applicable, and 29 CFR part 1911. SOURCE: 54 FR [redacted postal code], Oct. 31, 1989, unless otherwise noted. ## §1926.650 Scope, application, and definitions applicable to this 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…

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## 29 CFR 1926 (OSHA) - (ii) Designs shall be in written form and shall include the following: - (A) A plan indicating the sizes, types, and configurations of the materials to be used in the protective system; and - (B) The identity of the registered professional engineer approving the design. - (iii) At least one copy of the design shall be maintained at the jobsite during construction of the protective system. After that time, the design may be stored off the jobsite, but a copy of the design shall be made available to the Secretary upon request. - (d) Materials and equipment. (1) Materials and equipment used for protective systems shall be free from damage or defects that might impair their proper function. - (2) Manufactured materials and equipment used for protective systems shall be used and maintained in a manner that is consistent with the recommendations of the manufacturer, and in a manner that will prevent employee exposure to hazards. - (3) When material or equipment that is used for protective systems is damaged, a competent person shall examine the material or equipment and evaluate its suitability for continued use. If the competent person cannot assure the material or equipment is able to support the intended loads or is otherwise suitable for safe use, then such material or equipment shall be removed from service, and shall be evaluated and approved by a registered professional engineer before being returned to service. - (e) Installation and removal of support -(1) General. (i) Members of support systems shall be securely connected together to prevent sliding, falling, kickouts, or other predictable failure. - (ii) Support systems shall be installed and removed in a manner that protects employees from caveins, structural collapses, or from being struck by members of the support system. - (iii) Individual members of support systems shall not be subjected to loads exceeding those which those members were designed to withstand. - (iv) Before temporar…

Source excerpt

## 29 CFR 1926 (OSHA) - (ii) Installation of a support system shall be closely coordinated with the excavation of trenches. - (f) Sloping and benching systems. Employees shall not be permitted to work on the faces of sloped or benched excavations at levels above other employees except when employees at the lower levels are adequately protected from the hazard of falling, rolling, or sliding material or equipment. - (g) Shield systems -(1) General. (i) Shield systems shall not be subjected to loads exceeding those which the system was designed to withstand. - (ii) Shields shall be installed in a manner to restrict lateral or other hazardous movement of the shield in the event of the application of sudden lateral loads. - (iii) Employees shall be protected from the hazard of cave-ins when entering or exiting the areas protected by shields. - (iv) Employees shall not be allowed in shields when shields are being installed, removed, or moved vertically. - (2) Additional requirement for shield systems used in trench excavations. Excavations of earth material to a level not greater than 2 feet (.61 m) below the bottom of a shield shall be permitted, but only if the shield is designed to resist the forces calculated for the full depth of the trench, and there are no indications while the trench is open of a possible loss of soil from behind or below the bottom of the shield. ## Appendix A to Subpart P of Part 1926-Soil Classification - (a) Scope and application -(1) Scope. This appendix describes a method of classifying soil and rock deposits based on site and environmental conditions, and on the structure and composition of the earth deposits. The appendix contains definitions, sets forth requirements, and describes acceptable visual and manual tests for use in classifying soils. - (2) Application. This appendix applies when a sloping or benching system is designed in accordance with the requirements set forth in §1926.652(b)(2) as a method of protection for employees f…