June 28th saw the Beijing East Sixth Ring Road Reconstruction Project slurry TBM “Jinghua” successfully breakthrough on the project’s west line tunnel, marking the completion of the first line of China’s longest shield machine constructed expressway tunnel.
Manufactured by China Railway Construction Heavy Industry Corporation Limited (CRCHI), TBM “Jinghua” left the assembly line on September 27th 2020, at CRCHI Changsha headquarters. With an excavation diameter of 16.07m, this 4,300-tonne, 150m-long slurry TBM is the first of its kind to have been made in China.
The Beijing East Sixth Ring Road Reconstruction Project extends from the south, starting at the Beijing-Harbin Expressway, to the north, ending at Luyuanbei Street. It is designed with a speed limit of 80km per hour and has a total length of approximately 16km. The underground section of the project is about 7.4km, all constructed by TBM. The tunnels have a separate twin-tunnel configuration, each divided into three levels. The upper level serves as a smoke extraction channel, the middle accommodates a three-lane expressway, and the lower level serves as an evacuation and rescue channel. With a maximum depth of 75m it is the deepest tunnel in Beijing.
TBM tunnel construction on the project faced numerous challenges, including the use of a mega large diameter machine over a long distance at an ultra-deep depth in a highly sensitive environment. The machine was equipped with a host of innovative technologies to ensure rapid and safe tunnelling through complex geological conditions, mainly composed of sandy soil, water-rich and high-density sand, and interactive layers of silt and cohesive soil.
Since the launch of “Jinghua “in May 2021, the TBM crews reported an outstanding performance with a maximum daily advance rate of 24m and a maximum monthly advance rate of 542m.
The Beijing East Sixth Ring Road Reconstruction Project is a landmark project in the construction of the city’s sub-center. After opening to traffic, the project will promote the integration of the Tongzhou District and the administrative office area of the sub-center, significantly improving Beijing’s transportation services, promoting the integration of transportation in the Beijing-Tianjin-Hebei Region, and the creation of a comprehensive transportation system.