3304.4 Protection of Sides of Excavations

The sides of excavations shall be protected in accordance with the requirements of Sections 3304.4.1 through 3304.4.6.

The sides of all excavations, including related or resulting embankments, that are 5 feet (1524 mm) or greater in depth or height shall be supported in accordance with one or more of the following means. Where required by Section 3304.2, such means shall be indicated on drawings:

1. Sheeting, shoring, bracing, or by other retaining structures as may be necessary to prevent the sides of the excavation from caving in before permanent supports are provided. Such methods of protection shall be subject to special inspection in accordance with the provisions of Chapter 17; or

2. Excavation sides sloped not steeper than 45 degrees (0.79 rad) or stepped so that the average slope is not steeper than 45 degrees (0.79 rad) with no step more than 5 feet (1524 mm) high, provided such slope or step does not endanger any structure or temporary construction, including subsurface structures. Slopes or steps steeper than 45 degrees (0.79 rad), or steps more than 5 feet (1524 mm) high shall be permitted only where the registered design professional preparing the drawings required by Section 3304.2 determines, based upon the completion of a geotechnical investigation report acceptable to the commissioner, that the slopes or steps will be stable.

Exception: For a rock cut excavation, no protection is required, provided a registered design professional determines the rock cut will not be subject to shearing and will not otherwise be unstable before permanent supports are provided. Otherwise, the rock cut shall be stabilized in accordance with drawings prepared by the registered design professional.

See Section 3304.5.1.

Every site with an excavation shall be enclosed with a fence that meets the requirements of Section 3307.7.

All open edges of an excavation that are 6 feet (1829 mm) or greater in depth shall be protected by a guardrail system meeting the requirements of Sections 3308.7.1 through 3308.7.5, or by a solid enclosure at least 3 feet 6 inches (1067 mm) high. For the purpose of a guardrail system installed in accordance with this section to protect the open edge of an excavation, the term "floor" in Sections 3308.7.1 through 3308.7.5 shall mean "ground."

Exceptions:

1. The toeboard, when installed in conjunction with such excavation guardrail system, shall consist, at a minimum, of 1-inch × 6 inches (25 mm by 152 mm) lumber or metal plank and shall be at least 5¹/₂ inches (140 mm) high.

2. A toeboard is not required where the sheeting, shoring, bracing, or any other support of excavation extends at least 5¹/₂ inches (140 mm) above the top of the excavation.

3. A guardrail system or a solid enclosure is not required where access to the adjoining area is precluded.

4. A guardrail system or a solid enclosure is not required where side slopes are three horizontal by one vertical (33-percent slope) or flatter.

To provide necessary openings for intermittent operations, one or more sections of the guardrail system or solid enclosure may be hinged or supported in sockets. When supported in sockets, rails shall be so constructed that they cannot be jolted out. A button or hook may be used to hold the guardrail system or solid enclosure in a fixed position. Substantial chains or ropes may be used to guard such openings in such guardrail system or solid enclosure. Where so used, the chains or ropes shall be taut at the same height as the rails of the standard guardrail system.

Excavated material and superimposed loads, including but not limited to equipment and trucks used for soil or foundation work, shall not be placed closer to the edge of the excavation than a distance equal to one and one-half times the depth of such excavation unless the sides of the excavation have been sloped or sheet piled (or sheeted) and shored to withstand the lateral force imposed by such superimposed loads, or a registered design professional has determined the side of the excavation can adequately support the load imposed, with such support or determination shown on drawings required by Section 3304.2. In the case of open excavations with side slopes, the edge of excavation shall be taken as the toe of the slope.

Required protection for the sides of the excavation shall be installed as the excavation advances. The placement of permanent structures or fill in areas requiring support of excavation shall not begin until the support of excavation has been completed for such areas.