The results of modelling the impact of the construction of a multifunctional complex in a megacity in a dense urban environment on the existing subway and assessment of the safety of its further operation in order to develop a project for its reconstruction and the need to apply engineering measures for protection and strengthening are given in the chapter. The conducted assessment of conditions of operation of the subway is aimed at identification of potential risks and development of the project of its reconstruction. It also considers the need to apply engineering measures to protect and reinforce the structure to ensure its safe and efficient operation. The study highlights the importance of an integrated approach to the design and reconstruction of infrastructure facilities in conditions of intensive urban development, which will minimize negative consequences and increase the stability of existing structures.