TY JOUR TI Structural analysis of labor costs in the construction of tunnels by open, closed methods and the TOP DOWN method KW underground structure KW transport tunnel KW pedestrian tunnel KW metal structures KW open construction method KW closed construction method KW topdown method JO Construction and Architecture AU Korol, E.A. AU Chipova, Z.K. PY 2022 IS 10 PB Publishing Center RIOR