Body: "Tunneling" is underground passageway, dug through the surrounding soil/earth/rock and enclosed except for entrance and exit, commonly at each end.
J.N. Wang, DL Black, Charles Dowding are some authorities of "Tunneling".
Some questions in "Tunneling" involve history, civic planning, engineering.
understand the engineering, architectural design, and construction of tunnels is some of the cause to investigate "Tunneling".