Following the breakthrough of the right-line TBM in the Li-Lao section in early March 2021, on March 21, the left-line TBM of the Lijiazhuang Station—Laoshan Science and Technology City Station section in the Civil Engineering Section 10 of Qingdao Metro Line 4, undertaken by China Railway Construction Bridge Engineering Bureau Group, successfully broke through. With this, the Li-Lao section has successfully achieved double-line breakthrough. It is another section to achieve double-line breakthrough after the Li-Jiu section (Lijiazhuang Station—Jiushui East Road Station section) achieved double-line breakthrough last October, marking a new milestone in the construction.

The right-line section from Lijiazhuang Station to Laoshan Science and Technology City Station is 1,059.486 meters long, and the left-line section is 1,077.735 meters long. They are two parallel single-track tunnels constructed separately for the left and right lines, with a rail-surface burial depth of 17–32 meters. The tunnel body is mainly located in slightly weathered strata, with part of the small-chainage section in moderately weathered strata. The section passes beneath the Zhangcun River, a 500KV high-voltage transmission tower, water-rich faults, and densely populated residential areas, making construction relatively difficult.

To achieve the goal of double-line tunnel breakthrough in March, during the Spring Festival, Section 10, in accordance with the overall arrangements of Qingdao Metro Group and Qingdao Metro Line 4 Company, organized more than 220 project management and on-site construction personnel, with team members taking the lead, to give up the opportunity to reunite with their families during the Spring Festival and resolutely stay on the construction site. While carrying out epidemic prevention and control work, they vigorously advanced construction production. Through advance planning and meticulous deployment, all teams officially resumed work and production on the second day of the first lunar month, basically achieving the good situation of not stopping work during the Spring Festival and promoting production through intensive efforts, creating favorable conditions for subsequent construction.

Though flying high, the wild goose has not yet reached the blue clouds! On March 25, the right-line TBM in the Lao-Zhang section successfully launched, ensuring overall progress remained controllable and inspiring all construction participants to charge toward the goal of full-line breakthrough and embark on a new journey. In the next stage of work, Section 10 will make persistent efforts, fully raise ideological awareness and political stance, follow the working policy of “seeking truth from facts, upholding integrity and innovation, and achieving steady and long-term progress,” continue to carry forward the iron-army spirit of solid hard work, overcoming difficulties, and tenacious struggle, take the annual plan formulated by Qingdao Metro Line 4 Company as the goal, focus on construction progress as the main line, take “creating reputation and efficiency” as the lead, manage key links in process conversion well, consolidate responsibilities across all personnel, comprehensively improve the level of project management efficiency, and continue striving to help Qingdao Metro Line 4 open to traffic as soon as possible!