On January 9, the double-line tunnel of Qingdao Metro Line 5, constructed by China Railway 14th Bureau Group, successfully passed beneath the Jiaozhou-Jinan Railway, overcoming a Level-1 risk source. This laid a solid foundation for the smooth operation of the Spring Festival travel rush and provided valuable experience for shield tunnel construction beneath operating railway lines.

As a major transportation artery in Shandong Province, the Jiaozhou-Jinan Railway handles more than 150 trains per day. After departing from Ruichang Road Station and advancing 17 meters, the shield machine entered the section beneath the Jiaozhou-Jinan Railway. The affected area of the dual-line shield crossing beneath the railway totals 270 meters in length. The undercrossing section lies in a fractured zone with poor rock stability, making construction extremely difficult.

To ensure the safety of railway operations, the construction team increased the density of monitoring points. During the undercrossing of the operating railway line, 24-hour automated monitoring was adopted, and tunneling parameters were optimized in real time based on monitoring data. At the same time, the construction team used simultaneous grouting and secondary in-tunnel grouting to replenish grout in a timely manner, ensuring overall stability of soil pressure and adding safety assurance for the railway line in the undercrossing section.

Ultimately, over the course of 39 days, the builders completed the undercrossing task with almost zero settlement and zero deformation, ensuring normal operation of the railway line.

Qingdao Metro Line 5 is a backbone rail transit line encircling the eastern coastal urban area of Qingdao. Once completed, it will greatly enhance the networked operation function of the metro system in the eastern central urban area, improve the urban traffic environment and travel conditions for residents along the line, and drive the planned development of Dagang, CRRC Science and Technology Park, Joyful Coastal City, and the Yanjiashan area.