(3) "Trench" means an excavation having a depth greater than its width measured
at the bottom.
(4) "Trench jack" means a screw or hydraulic jack used as a brace in a trench
(5) "Trench shield," sometimes called a trench box, means a trench shoring
system composed of steel plates and bracing, welded or bolted together, which can
be moved along as work progresses.
(6) "Uprights" means the vertical members of a trench shoring system.
History: 1979 AC.
R 408.40931 Locating utility lines.
Rule 931. (1) An employer shall not excavate in
street, highway, public
place, a private easement of a public utility, or near the location of a public utility
facility owned, maintained, or installed on a
customer's premises, without having first ascertained the location of
underground facilities of a public utility in the proposed area of excavation.
(2) Upon receiving the information from the public utility, an employer shall
exercise reasonable care when working in close proximity to the underground
facilities of any public utility. If the facilities are to be exposed, or are likely to be
exposed, only hand digging shall be employed in such circumstances and such support,
as may be reasonably necessary for protection of the facilities, shall be provided
in and near the construction area.
(3) When any contact with, or damage to, any pipe, cable, or its protective
coating, or any other underground facility of a public utility
occurs, the public utility shall be notified immediately by the employer responsible
for operations causing the damage. If an energized electrical cable is severed, an
energized conductor is exposed, or dangerous fluids or gases are escaping from a broken
line, the employer shall evacuate the employees from the immediate area while
awaiting the arrival of the public utility personnel.
History: 1979 AC.
R 408.40932 Excavation; consideration of soil types; water; slide hazards.
Rule 932. (1) If different textured soils are encountered in the side of an excavation,
each soil type of the excavation shall be cut to the proper angle of repose, except that the
slope shall not steepen between the toe of the slope and the ground level where soft clay
or running soil is encountered in the lower cut.
(2) An employee shall not work in an excavation in which there is accumulated
water or in which water is accumulating unless precautions have been taken to protect
employees against the hazards posed by water accumulation. The precautions necessary
to protect employees adequately vary with each situation, but may include special support
or shield systems to protect from cave-ins, water removal to control the level of
accumulating water, or the use of a safety harness and lifeline.