Excavation protective systems requirements

A protective system is not required when the excavation is entirely in stable rock, or when the excavation is less than 5 feet deep and a competent person’s ground examination shows no indication of a potential cave-in. See Protection of employees in excavations at 1926.652(a)(1) and the exceptions at 1926.652(a)(1)(i) and (ii).

• If any sign of unstable soil or other cave-in risk is found by the competent person, a protective system must be provided regardless of depth.
• "Stable rock" must be an excavation made entirely in that material to qualify for the exception.

Protective systems must be able to resist without failure all loads that are intended or could reasonably be expected to be applied or transmitted to the system. See 1926.652(a)(2).

• That means you must account for foreseeable loads such as equipment, stockpiled materials near the edge, adjacent traffic, and surcharges.
• If the competent person determines additional loads are possible, the protective system must be designed to handle them.

You must select and construct sloping or benching systems using one of the approved options in paragraph (b): Option 1 (the allowable slopes), Option 2 (Appendices A and B), Option 3 (tabulated data), or Option 4 (design by a registered professional engineer). See Design of sloping and benching systems at 1926.652(b).

• Use Option 1 if your excavation can meet the simple slope requirements in 1926.652(b)(1).
• Use Option 2 when you will apply the more detailed procedures in the appendices.
• Use Option 3 when you have verified tabulated data (tables/charts) that are appropriate for site conditions.
• Use Option 4 when a registered professional engineer prepares and approves the design.

Using Option 1, excavations must be sloped no steeper than 1.5 horizontal to 1 vertical (34 degrees from horizontal) and the configuration must match the Type C soil slopes shown in Appendix B. See 1926.652(b)(1)(i) and (ii).

• Before using this option, ensure you have correctly classified the soil as Type C (consult Appendix B as directed by the standard).
• If soil conditions or site factors differ, consider Options 2–4 for a safer, site-specific design.

Written tabulated data must identify the parameters that affect selection, set out the limits of use (including safe slope magnitudes and configurations), and include any explanatory information needed to choose the correct system. At least one copy of the tabulated data, identifying the registered professional engineer who approved it, must be kept at the jobsite during construction. See 1926.652(b)(3)(ii) and (iii).

• Keep the approved tables/charts on site while constructing the protective system so workers and the competent person can verify applicability.
• The tabulated data must clearly state the limits to avoid misuse.

A registered professional engineer must approve designs for sloping/benching (Option 4) and for support, shield, or other protective systems when Options 1–3 are not used. The engineer must provide written designs and identify the safe slopes/configurations and their approval. See 1926.652(b)(4) and 1926.652(c)(4).

• The written design must include the magnitude of slopes and configurations determined to be safe and the engineer’s identity (1926.652(b)(4)(ii)).
• At least one copy of the design must be maintained at the jobsite while the slope or protective system is being constructed (1926.652(b)(4)(iii) and 1926.652(c)(4)(iii).

You can use a manufacturer’s tabulated data for aluminum hydraulic shoring only by following all the manufacturer’s specifications, recommendations, and limitations, and any deviation requires the manufacturer’s specific written approval kept at the jobsite during construction. See 1926.652(c)(2)(i)–(iii).

• If the manufacturer’s tabulated data cannot be used, designs must follow Appendix D as stated in the standard.
• Keep the manufacturer’s specifications and any written approval for deviations on site while building the protective system.

Materials and equipment used for protective systems must be free from damage or defects; when they are damaged, a competent person must examine and evaluate their suitability for continued use, and if the competent person cannot assure safety they must be removed and approved by a registered professional engineer before reuse. See 1926.652(d)(1)–(3) and the removal/engineer requirement in the standard text.

• Do not return damaged components to service unless they pass the competent person’s evaluation or are reapproved in writing by a registered professional engineer.
• Manufactured equipment must also be used and maintained consistent with the manufacturer’s recommendations (1926.652(d)(2)).

Support system members must be securely connected to prevent sliding or kickouts; installed and removed so employees are protected from cave-ins or being struck by members; individual members must not be overloaded; and removal must begin at and progress from the bottom with slow release of members while watching for signs of failure. See 1926.652(e)(1)(i)–(v).

• Before temporarily removing members, install other structural members if needed to carry the loads (1926.652(e)(1)(iv)).
• Coordinate installation closely with trench excavation and follow e(2) requirements for trench support systems.

You may excavate up to 2 feet below the bottom of the members of a support system only if the system 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 soil loss from behind or below the support. See 1926.652(e)(2)(i).

• This exception is conditional: the support must be designed for the full trench depth and a competent person must verify no signs of soil loss during operations.
• If signs of loss or instability appear, stop excavation and protect employees immediately.

No — employees are not allowed in shields while shields are being installed, removed, or moved vertically. See 1926.652(g)(1)(iv).

• Employees may enter shields only after the shield is properly installed and stable and appropriate means of access/egress and protection from cave-in hazards are in place (1926.652(g)(1)(iii)).

Employees must not work on the faces of sloped or benched excavations at levels above other employees unless those lower employees are adequately protected from falling, rolling, or sliding material or equipment. See 1926.652(f).

• Protection can include barriers, catch platforms, or other controls that prevent material from reaching lower workers.
• The competent person should evaluate and implement appropriate protections before allowing work at different levels.

Shields must be installed to restrict lateral or other hazardous movement of the shield if sudden lateral loads are applied, meaning they must be braced, keyed, or otherwise secured to prevent shifting under such loads. See 1926.652(g)(1)(ii).

• Consider adjacent equipment, spoil piles, or side-slope exposures that could create lateral forces and secure shields accordingly.
• The competent person must ensure the installation method prevents hazardous movement during foreseeable events.

Tabulated data must identify parameters that affect selection, state limits of use, include explanatory information to aid correct selection, and at least one copy identifying the registered professional engineer who approved the data must be maintained at the jobsite during construction. See 1926.652(c)(3)(ii)–(iii).

• Keep the approved tables/charts on site while constructing or installing the protective system so the competent person and crew can verify compliance.
• After construction you may store the data off-site, but it must be produced upon request by the Secretary.

Manufactured materials and equipment used for protective systems must be used and maintained in a manner consistent with the manufacturer’s recommendations to prevent employee exposure to hazards. See 1926.652(d)(2) and 1926.652(c)(2)(i).

• Do not modify or reuse components contrary to the manufacturer’s limitations unless you have the manufacturer’s specific written approval on site (1926.652(c)(2)(ii)–(iii)).
• Regular inspections by a competent person and prompt repair or removal of damaged items are required (1926.652(d)(3)).

Removal of support members must begin at and progress from the bottom of the excavation, with members released slowly while watching for signs of failure, and backfilling must progress together with the removal of support systems. See 1926.652(e)(1)(v)–(vi).

• Do not remove supports faster than the backfill can stabilize the excavation.
• Take additional precautions before temporarily removing members (such as installing other structural members) to carry imposed loads (1926.652(e)(1)(iv)).

Employees must be protected from cave-in hazards when entering or exiting areas protected by shields, which means providing safe access/egress and ensuring the shield is properly installed and stable before entry. See 1926.652(g)(1)(iii).

• Examples of protection include ladders or steps that do not compromise shield stability, staging, or other engineered access that keeps workers out of exposed soil faces.
• The competent person should confirm the access method is safe before workers use it.

The tabulated data must identify the registered professional engineer who approved the data, and a copy with that identification must be maintained at the jobsite during construction of the protective system. See 1926.652(b)(3)(iii) and 1926.652(c)(3)(iii).

• This requirement ensures qualified professional approval for the tabulated data used at the site.
• Keep the approved data available on site during construction and make it available to the Secretary upon request.

A registered professional engineer’s written design must include a plan indicating the sizes, types, and configurations of the materials to be used and the identity of the registered professional engineer approving the design. See 1926.652(c)(4)(ii)(A)–(B).

• Keep at least one copy of the design at the jobsite while constructing the protective system (1926.652(c)(4)(iii)).
• The plan should be specific enough for the competent person and crew to install and verify correct materials and configuration.

You may deviate from the manufacturer’s specifications only after the manufacturer issues specific written approval, and that written approval (and the manufacturer’s specifications) must be kept at the jobsite during construction of the protective system. See 1926.652(c)(2)(ii)–(iii).

• Keep both the original manufacturer’s recommendations and the written permission to deviate on site while the protective system is being constructed.
• After construction you may store the documents off-site, but they must be made available to the Secretary on request.

A competent person must examine damaged material or equipment used for protective systems and evaluate its suitability; if the competent person cannot assure it is safe, the material or equipment must be removed from service and evaluated and approved by a registered professional engineer before being returned to use. See 1926.652(d)(3).

• Don’t rely on visual checks alone—have a qualified competent person perform the examination and document findings as needed.
• If a registered professional engineer is required to reapprove the item, obtain written approval before reuse.