Recommendations for the use of underground dual-use structures in Ukrainian realities

Abstract

The purpose of the work is to perform an analysis of the world experience of multi-purpose use of underground structures and to provide recommendations on monitoring the technical condition and technology of repair and restoration works of underground and buried dual-use objects for their operation in the conditions of Ukrainian realities. The main areas of use of underground structures for additional purposes are considered. In particular, for the equipment of warehouses, isothermal factories, specialized research laboratories, medical institutions with special conditions, tourist facilities. Under martial law, underground facilities are also used to shelter civilians, organize the production of defense products, hold mass cultural events, and create first aid stations for victims. There are two main categories of dual-use underground structures. The first one includes mining workings in the abandoned areas of mines. The main requirements for the workings are a large cross-section, satisfactory natural stability, the absence of harmful gases in the mine atmosphere, and the absence of the threat of flooding. It is desirable to be able to drive vehicles from the earth's surface directly to the required object. These requirements are implemented mainly in mines for the extraction of non-metallic building materials. The second category includes underground hydraulic structures, transport tunnels, basements of industrial enterprises and residential buildings. The main requirements for the performance of additional functions are the provision of full operation of the building for its primary purpose and the creation of safe conditions for people without special knowledge and skills. To assess the possibility of expanding the operational capabilities of underground structures, a methodology for their survey has been developed. The methodology involves a visual assessment of the state of rock exposures and fasteners, determination of the strength of rocks and concrete mainly using non-destructive control methods, detection of cavities behind the shell of an underground structure using the vibroacoustic method. In some cases, control drilling is performed. The presence of people without personal protective equipment in the dual-use underground structure places higher requirements on the stability of structures. To increase the stability of the mine workings, additional fixing of the roof of the workings with anchors, application of shotcrete on rock outcrops and the surface of the destroyed support, creation of canopies in areas where people are concentrated are provided. Increasing the stability of underground structures, which are not related to the extraction of minerals, is achieved by strengthening and installing additional load-bearing structures. To improve the waterproofing of the underground structure, it is recommended to fill the cavities behind the shell, eliminate filtering fractures, repair the seams between the sections of support, and apply a penetrating coating.