Underground space development resulting from increased urban migration

Worldwide urbanization has resulted in the creation of so called “megacities” with populations of 10 million or more. It is estimated that 68% of the world’s population will reside in urban centers by the year 2050 up from 55% in 2018 [1]. This pace of urbanization is staggering, especially in China where urban populations have more than doubled over the last 30 years, while urban land extent has more than tripled [2]. Today, urban planners and engineers are faced with challenging decisions regarding land management planning. To manage this population increase, there is a need to cultivate urban underground space to reduce congestion on the surface, control urban sprawl, and provide opportunities to re-purpose land for recreational space. This discussion paper provides a review of several recommended practices for urban underground space development addressing planning, intended function, and environmental sustainability/resiliency.