The employer shall ensure at a construction site of a building or other construction work that.-
(a) where there is a danger of falling or sliding of material from the roof face or wall of a tunnel, adequate measures such as shoring, supporting by means of rock bolts, segments or steel set are taken for the safety of building workers:
(b) the excavated areas are made safe by use of suitably designed and installed steel sets, rock bolts or similar other safe means;
(c) the responsible person referred to in rule 121 examines and inspects the work places in a tunnel before the commencement of work in such tunnel, and at regular intervals thereafter to ensure safety of the building workers in such tunnel; and
(d) the portal areas of the tunnel with loose soil, or rock, likely to cause injuries to a person are adequately protected with supports.