Abstract: According to the statistics of large-diameter shield tunnel projects (with a cutterhead diameter 10 m≤d＜14 m) and super-large-diameter shield tunnel project (with d≥14 m) built in China by the end of 2024, including completed ones and commenced but not yet completed ones, there were 190 large- and super-large-diameter shield tunnel projects built in China by the end of 2024, including 100 large-diameter shield tunnel projects, and 90 super-large-diameter shield tunnel projects. The situation of large-diameter shield tunnels commenced in China by the end of 2024 was analyzed by provincial-level administrative region, commencement year, shield launching year, underpass area (land/waters), stratum conditions, shield cutterhead diameter, shield section length, shield type, cutterhead structure form, tunnel purpose, etc. The results are as follows: (1) The top four provincial-level administrative regions with the most large- and super-largediameter shield tunnels were Shanghai Municipality (45 projects), Guangdong Province (39 projects), Zhejiang Province (36 projects), and Jiangsu Province(22 projects). Indicating that most of the large- and super-large-diameter shield tunnels are primarily located in Yangtze River Delta and Pearl River Delta. (2) Before 2005, the construction of large-diameter shield tunnels progressed slowly, and only a total of 9 large-diameter and super-large-diameter shield tunnel projects were commenced. From 2006 to 2015, there was a stable development period, during which a total of 40 large-diameter and super-large-diameter shield tunnel projects were commenced. In 2016, a peak period of construction began. From 2016 to 2020, 50 large-diameter and super-large-diameter shield tunnel projects were commenced. From 2021 to 2024, the quantity of projects remained high, and 91 projects were commenced, with an average of about 23 projects commenced each year, marking the climax period of construction. (3) Large-and super-large-diameter shield tunnel projects only passing under land and those only passing under waters accounted for about 39.5% and 54.7% respectively. In addition, large- and super-large-diameter shield tunnel projects passing under both waters and land accounted for about 5.8%. There were rather many shield tunnel projects passing under waters. (4) The quantities of large- and super-large-diameter shield tunnel projects passing through soft soil strata, composite strata, and hard rock strata were 97, 86, and 7 respectively, accounting for approximately 51.0%, 45.3%, and 3.7% respectively. There were rather few shield tunnel projects passing through hard rock strata. (5) The shield cutterhead diameters were mainly distributed in 11－12 m, 14－15 m, and 15－16 m, accounting for approximately 25.8%, 22.1%, and 21.0% respectively. The maximum cutterhead diameter of the shield tunnels currently under construction in China is 17.50 m. (6) There were 92 shield tunnel projects with a shield section length of 1 000－3 000 m, accounting for the largest proportion, i.e., about 48.4%. There were 45 shield tunnel projects with a shield section length of 3 000－5 000 m, accounting for about 23.7%. There were 4 shield tunnel projects with a length of more than 10 000 m. (7) There were 169, 16, and 6 large- and super-large-diameter shield tunnel projects using slurry shield, EPB shield, and dual-mode shield respectively (among which both EPB shield and dual-mode shield were used in the expansion of subsequent Western Channel for Hangjiahu southward drainage), indicating that most (about 89%) largediameter shield tunnels were constructed by slurry shields. Meanwhile, multi-mode shields have been applied in tunneling. (8) The quantities of large- and super-large-diameter shield tunnel projects using the shields with ordinary, normal pressure, and grid cutterhead structure forms were 102, 90, and 2 respectively. For the large-diameter shields, the ordinary cutterhead structure form was mainly used. For super-large-diameter shields, the normal pressure cutterhead structure form was mainly used. (9) In terms of tunnel purpose, the large-diameter shield tunnels were mainly in the fields of railways (including intercity/intra-city railways), urban roads, metros, and highways, accounting for 92%, and the super-large-diameter shield tunnels were mainly in the fields of urban roads, railways (including intercity/intra-city railways), and highways, accounting for about 95.6%.

Key words: large-diameter shield tunnel, statistics and analysis, stratum conditions, cutterhead diameter, shield section length, shield type, cutterhead structure form, tunnel purpose