The 2022 Winter Olympic Games venues are located in Beijing and Zhangjiakou in Hebei Province, northwest of Beijing. To create an efficient rail link between the cities, Chinese railway engineers are building a 174 kilometer long high-speed line. Designed for speeds of up to 350 kilometers per hour, it reduces the previously required 3 hours of travel time to just 1 hour.
A key structure of the large-scale project is the approximately 6 kilometer long twin-tube Qinghuayuan Tunnel, for which Herrenknecht has supplied two Mixshields with a diameter of 12.61 meters. Experts consider construction of the tunnel a complex challenge, as it leads from the Beijing North Station under densely populated urban areas in the immediate vicinity of existing underground infrastructure such as subway lines. Herrenknecht Mixshields are ideally equipped for such tasks. The support pressure is managed precisely using an automatically controlled air cushion. As a result, heterogeneous geologies and high water pressures can also be reliably managed, even with large excavation diameters.
The first of the two Mixshields began its drive in November 2017. In just 10 months, the Chinese site crews completed it successfully after a total of 1,742 meters. The second Mixshield, launched later, mastered the breakthrough in November 2018.