The employer shall ensure at a construction site of a building or other construction work that,—
(a) surroundings of a shaft used in excavation or tunnel work are protected from being washed away by construction of sufficient height;
(b) where a building worker is required to enter a shaft at an excavation or tunneling work, safe means of access is provided for such entry;
(c) every shaft at excavation or tunneling work is provided with a steel casing, concrete piping, timber shoring or other materials of adequate strength for the safety of building workers working in such shaft:
(d) such casing and bracing are provided to a shaft at an excavation or tunneling work up to the depth of such shaft at an excavation or tunneling work according to the appropriate design for such casing and bracing; and
(e) a reinforced concrete raft and beam is provided around the opening of a shaft at an excavation or tunneling work if the ground surrounding such opening is unstable or unsafe.