On the morning of June 20, the super-large-diameter shield tunneling machine "Jingbin Innovation" for the Beijing-Binhai Intercity Railway was successfully launched in Tianjin, marking that the Tianjin Airport No. 2 Tunnel of the Beijing-Binhai Intercity Railway has entered the stage of full-speed shield tunneling construction, laying a solid foundation for the tunnel to be completed on schedule.

The reporter learned from the China Railway Beijing Group that the Beijing-Binhai Intercity Railway is an important part of the "railway-integrated Beijing-Tianjin-Hebei" network. In December 2022, the Baodi to Beichen section and the Baodi Station, Baodi South Station, and Beichen Station along the line were opened for operation. At present, the second-phase project from Dongli to Binhai New Area, invested and constructed by the Beijing-Tianjin-Hebei Intercity Railway Investment Co., Ltd., is being accelerated.

Tianjin Airport No. 2 Tunnel is located in Dongli District, Tianjin. It connects to the Tianjin Airport underground station to the north and, after passing beneath the elevated section of the Jishan Expressway to the south, emerges to the surface. The tunnel has a total length of 8,663 meters and is a single-tube double-track tunnel, of which the shield-driven section is 7,720 meters. It is a key control project for the entire line.

To further improve tunneling efficiency, the tunnel is implemented in two sections. The "Jingbin Innovation" shield tunneling machine launched this time has an excavation diameter of 13.8 meters, an overall length of 130 meters, a total weight of 3,000 tons, and a total installed power of 8,900 kilowatts. It will be responsible for the tunneling task of the 4,882-meter shield section of Tianjin Airport No. 2 Tunnel. The smooth launch of "Jingbin Innovation" will form a "joint tunneling" posture with the previously launched "Jingbin Synergy," further accelerating the construction speed.

Wang Jinsheng, senior project manager of the Tianjin Engineering Command of the Beijing-Tianjin-Hebei Railway Company, introduced that the geological environment of the tunneling section of the "Jingbin Innovation" shield tunneling machine is complex, including clay strata and earthquake liquefaction zones. It will pass through risk sources such as the Jishan Expressway, the Xijian River, and the Jinbei Highway. There are many construction restriction factors, high technical difficulty, and complex hydrogeological conditions, placing extremely high demands on the performance and technology of the shield tunneling machine.

To ensure safe and efficient tunneling by the shield machine, the project team of China Railway 14th Bureau Group carried out targeted selection design and manufacturing of the shield machine, equipped it with a number of advanced intelligent technologies such as a cutterhead and cutting tool detection system and a visualization system for the excavation chamber, and adopted a dual design of "large alloy + diamond" for the cutting tools, enhancing the wear resistance of the tools and greatly improving the safety and durability of the shield machine.

In the future, after the entire Beijing-Binhai Intercity Railway is completed and opened to traffic, a large comprehensive transportation hub integrating railways, civil aviation, subways, and other modes of transportation will be formed at Tianjin Binhai Airport. The line will connect with multiple lines such as the Beijing-Tangshan Intercity Railway and the Beijing-Tianjin Intercity Railway, further improving the regional road network structure of Beijing-Tianjin-Hebei, providing more convenient and rapid travel services for the people of the Beijing-Tianjin-Hebei region, and helping the integrated development of the regional economy.