Excavations, shafts, earthworks, underground works and tunnels

• Pages: 47-54

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9. Excavations, shafts, earthworks, underground

works and tunnels

9.1. General provisions

9.1.1. Adequate precautions should be taken in any excavation, shaft,

earthworks, underground works or tunnel:

(a) by suitable shoring or otherwise, to guard against danger to workers from a fall or

dislodgement of earth, rock or other material;

(b) to guard against dangers arising from the fall of persons, materials or objects or the

inrush of water into the excavation, shaft, earthworks, underground works or

tunnel;

(c) to secure adequate ventilation at every workplace so as to maintain an atmosphere

fit for respiration and to limit any fumes, gases, vapours, dust or other impurities to

levels which are not dangerous or injurious to health and are within limits laid

down by national laws or regulations;

(d) to enable the workers to reach safety in the event of fire, or an inrush of water or

material;

(e) to avoid risk to workers arising from possible underground dangers such as the

circulation of fluids or the presence of pockets of gas, by undertaking appropriate

investigations to locate them.

9.1.2. Shoring or other support for any part of an excavation, shaft, earthworks,

underground works or tunnel should not be erected, altered or dismantled except under

the supervision of a competent person.

9.1.3. Every part of an excavation, shaft, earthworks, underground works and

tunnel where persons are employed should be inspected by a competent person at times

and in cases prescribed by national laws or regulations, and the results recorded.

9.1.4. Work should not commence therein until the inspection by the competent

person as prescribed by national laws or regulations has been carried out and the part of

the excavation, shaft, earthworks, underground works or tunnel has been found safe for

work.

9.2. Excavations

9.2.1. Before digging begins on site:

(a) all excavation work should be planned and the method of excavation and the type

of support work required decided;

(b) the stability of the ground should be verified by a competent person;