Reasonable Treatment Range of Karst Cave Encountered by Super-Large Diameter Shield Tunnel in Strongly Karst-Developed Area

Table 1

Treatment range of shield tunnel with a diameter of about 6 m.

Engineering case	Tunnel outer diameter (m)	Karst cave development	Treatment range
Shield tunnel of Guangzhou metro line 9 (data from Qian [14])	6	There are 132 karst caves, including 93 unfilled karst caves, 39 half filled and fully filled karst caves
Shield tunnel of Nanning metro line 3 (data from Xie [19])	6	There are 178 karst caves, including five unfilled karst caves, 66 half filled karst caves, and 107 fully filled karst caves
Shield tunnel of Shenzhen metro line 16 (data from Zhang [20])	6.2	There are 258 karst caves, including 220 unfilled karst caves, 38 half filled and fully filled karst caves
Shield tunnel of Kunming metro line 4 (data from Liu et al. [21])	6.2	There are 219 karst caves, including 44 unfilled and half filled karst caves and 175 fully filled karst caves
Shield tunnel of Wuhan metro line 27 (data from Zhang [22])	6.2	There are 536 karst caves, including 241 unfilled karst caves, 130 half filled karst caves, and 165 fully filled karst caves
Shield tunnel of Changsha metro line 3 (data from Ma [23])	6.2	There are 89 karst caves, including 14 unfilled karst caves, 75 half filled and fully filled karst caves