Practice and multidimensional-coupling planning methods of underground space utilization of megalopolis

As megacities enter a phase of stock improvement as well as intensive and efficient development, underground space planning has evolved from an engineering issue into a strategic topic concerning territorial security, resource allocation efficiency, and urban resilience. The establishment of a clear hierarchical underground space planning system and the improvement of underground space control methods are the important prerequisites for ensuring the sustainable utilization of underground space resources. In line with the territorial spatial planning system, the systematic planning and control methods have been explored from the perspective of strictly adhering to the ecological bottom line, coordinating functional facilities, and guiding development of key areas. Red line for underground space has been delineated based on three-dimensional geological model, the overall layout guidance of various functional facilities has been strengthened and a comprehensive evaluation method for the development potential of key areas has been developed. This study hopes to promote the integrated utilization of above-ground and underground space resources.