29 CFR 1926.652
Requires that each employee in an excavation be protected from cave-ins by an adequate protective system designed under the section (sloping/benching, support/shoring, or shield systems), except where the excavation is made entirely in stable rock or is less than 5 feet deep and a competent person's examination of the ground provides no indication of a potential cave-in. Protective systems used in excavations more than 20 feet deep must be designed by (or, for tabulated-data designs, approved by) a registered professional engineer.
29 CFR 1926.1153
29 CFR 1926.1201
29 CFR 1926.1427
29 CFR 1926.451
29 CFR 1926.501
29 CFR 1926.62
Pin a building and we'll surface every amendment, effective-date change, and filing deadline as it happens.