On the development of the code of practice "Concrete and reinforced concrete structures of transport facilities, tunnels, and metro systems. Repair regulations"

Introduction. Transport tunnels and metro systems are complex engineering structures subjected to significant loads and diverse environmental impacts, necessitating a systematic approach to ensuring their operational reliability. Concrete and reinforced concrete structures, which form the backbone of these facilities, frequently experience damage that compromises their functional characteristics and safety. The need to update and systematize approaches to repairing of such structures has become urgent due to updating of the regulatory framework, increasing demands for infrastructure resilience, and the adoption of advanced technologies. The aim of developing the draft Code of Practice is to establish the technical foundations for designing, organizing, and conducting of the repair and restoration work on concrete and reinforced concrete structures of transport tunnels and metro systems. This applies to structures under construction, in operation, or temporarily taken out of service, which are subject to constant exposure to water and water vapor, loads, and impacts from surrounding rock masses. The work also considers the possibility of restoration being limited to the internal contour of the lining or the structural elements of subsurface sections. Materials and methods. As part of the work, an analysis of existing regulatory documents in the field of repair of concrete and reinforced concrete structures was carried out, along with the review of provisions and recommendations of international organizations. Additionally, the results of research and development (R&D) were studied and taken into account. Results. The result of the work is a Draft Code of Practice that includes key provisions for the design, organization, and implementation of repair works, including methods for restoration, reinforcement, and sealing of the structures. The project incorporates modern repair technologies and takes into account the operational specifics of underground transport facilities. The document has undergone a stage of public discussion, received expert evaluations from professional communities and authorities, and is being prepared for approval and implementation. Conclusions. The implementation of the Code of Practice will enhance the quality and reliability of repair works, reduce costs, and extend the intervals between repairs, thereby contributing to the sustainable development of transport infrastructure.