Recently, with the "Jiaozhou Bay No. 12" shield machine breaking through the ground, the right-line tunnel of the Luzhou Road Station–Lanzhou West Road Station section (the "Lu-Lan section") of the Qingdao Metro Line 8 Branch was successfully completed 35 days ahead of schedule. The Lu-Lan section consists of twin-tube single-track tunnels constructed by the shield method, with a section length of 835 meters. The route starts from Luzhou Road Station, runs beneath Hangzhou Road in a northerly direction, passes under the Yunxi River, the Hangzhou Road Experimental Primary School bridge, and the planned Line 10 section, and then connects to Lanzhou West Road Station.

To ensure the smooth launch and tunneling of the shield machine, the Third Construction Branch of Qingdao Metro Group carefully planned and repeatedly studied every process, from equipment selection, modification, and transportation to underground assembly. During the shield machine modification, a spoke-type cutterhead structure was adopted and the cutterhead opening ratio was increased, solving a series of problems such as the easy formation of mud cakes when the shield machine passes through strongly weathered mudstone, and ensuring good equipment performance. At the same time, by modifying the battery locomotive anti-drowsiness pedal and the pneumatic interlock brake system, and adding anti-rollback hook devices and section anti-rollback car stoppers, unexpected rolling of the battery locomotive was prevented. Digital and intelligent means were also used to strengthen tunneling safety management and technical control, and through real-time monitoring, data analysis, and other means, the safety and stability of shield construction were ensured.

During shield tunneling, the Third Construction Branch of Qingdao Metro Group monitored the tunneling attitude of the shield machine in real time, operated the shield propulsion zones according to the soft and hard distribution of the strata, set the thrust and advance speed, and simultaneously intensified monitoring of the surrounding environment such as road surfaces, buildings, and pipelines, achieving precise control of the shield attitude and ground settlement. At the same time, special efforts were carried out on safety control and discussion of segment precasting and assembly standards to ensure that the segment floating amount and stratum loss rate remained stable during construction, achieving the goals of a formed tunnel with no leakage and segment assembly misalignment within 3 millimeters, thereby supporting high-quality shield construction.