Innovative Engineering Solutions for Improving Operational Safety and Efficiency of Subways with Two-way Tunnels

The paper considers the problems of improving the operational safety of the two-way tunnel subway under weather conditions characteristic of Russian megapolises. A significant difference is indicated between annually mean, monthly mean and extreme outdoor air temperatures affecting thermodynamic parameters of the intra-subway atmosphere in Russia and foreign countries having subways. Comparative characteristics are given for the factors determining temperature regimes of the subway lines with single-way and two-way tunnels in case conventional ventilation schemes are used. The paper also describes alternative ventilation schemes involving constructive elements widely used for venting motor-road tunnels. Based on specific initial data, calculations have been performed whose results characterize temperature distribution in running single-way and two-way tunnels vented by using the ventilation scheme comprising vent ducts and air recirculation. The efficiency of the two-way tunnel ventilation scheme comprising a ventilation duct and air recirculation has been justified. Mathematical simulation of the dynamics of smoke propagation in case of a fire in tunnels and at stations has been accomplished. Efficiency of the emergency ventilation scheme comprising a vent duct in smoke protection of the fire evacuation passages for people and in smoke removal has been proved. The paper presents such station complex layout solutions that, contrary to historical prototypes, imply integrating the station ventilation and smoke removal systems into the general structure of the station space-planning solutions so that they are in close vicinity of all the designed passenger flows with retention of the comfortable space necessary for passengers.