Volume 96 • Number 3 • March 2022 • Mumbai • Pages 60 • ` 175 FIRE SAFETY IN UNDERGROUND TUNNELS 4:31 3:59 3:24 0 1 2 3 4 5 6 7 Fire resistance (hr) HSC+ P HSC+ S HSC HSC HSC HSC (135° bent + (PP (Steel closer ties) fibers) fibers)