Technological efficiency in the use of dual-purpose urban underground facilities

The development of urban areas, including megacities and agglomerations inevitably affects the underground space. Taking into account the possible use of the underground facilities as protective structures, the designers do not always pay due attention to the issue of their dual use despite the regulatory requirements for the design of underground facilities. At the same time, densely populated mountain areas, on the one hand, are very promising from the perspective of accommodating the urban transport, public, commercial and other facilities under the ground, and on the other hand, there is a certain concern about the structural safety of these facilities for protecting population during emergencies. The article aims to determine whether it is feasible to use urban underground facilities as protective shelters in the mountainous regions of Russia (using the example of Primorsky Territory). The classification of underground spaces from the life safety improvement standpoint was established. The underground structures suitable for collective protection of the population were systematized. The article identified conditions and factors that determine the feasibility of using underground facilities of urban infrastructure and industrial enterprises as dual-use objects, taking into account the influence of geological and mining technological conditions. The article specified technological parameters that are taken into account when justifying the feasibility of using underground structures for protective purposes. In particular, rational parameters of underground structures have been established when they are used as dual-use objects. The article revealed a range of dependencies between the number of sheltered people and the usable areas and volumes of an underground structure, taking into account various space-planning decisions and ventilation conditions