Urban areas are becoming more densely built: consequently, surface space is less available. The United Nations recently projected that 68% of the world’s population would live in urban areas by 2050 (up from 55% at present). Thus, it is expected that cities, counties, and states will increasingly look to underground structures as alternatives to surface infrastructure to address space constraints. The increase in the number and extent of tunneling projects also increases the complexity of urban infrastructure development, necessitating structural and geotechnical or tunneling engineers to collaborate closely to deliver an efficient and practical design while managing impacts on existing structures. …