The concentration of the dust particles of the size 0.5 to 5 microns adjacent to the working face should not be more than
A. 200 particles/cm3
B. 250 particles/cm3
C. 300 particles/cm3
D. 450 particles/cm3
Answer: Option D
This Question Belongs to Civil Engineering >> Tunnel Engineering
Related Questions on Tunnel Engineering
A. (i) and (ii) are correct
B. (iii) and (iv) are correct
C. (i) and (iv) are correct
D. (ii) and (iii) are correct
Which of the following lining material is useful for shield driven tunnels in sub aqueous regions?
A. Stone masonry
B. Timber
C. Cast iron
D. Cement concrete
Which of the following methods of tunneling is used for long tunnels at great depths?
A. Army method
B. Needle beam method
C. Austrian method
D. English method
A. Only up holes
B. Only down holes
C. Horizontal or up holes
D. Horizontal down or up holes
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