CRCHI Mega Slurry TBM with a Maximum Excavation Diameter of 16.07 m Rolls Off the Production Line

2020-09-27

On September 27, a mega slurry TBM with a maximum excavation diameter of 16.07 m rolled off the production line in CRCHI’s first industrial park in Changsha, China. This “Giant” is 150 m long and weighs 4,300 t. This slurry TBM, named "Jinghua", which will be used for the construction of Beijing East 6th Ring Road Tunnel.

The gigantic slurry TBM, like a steel dragon lying in the workshop, is higher than a 5-storey building. Its cutterhead is painted with a red Peking opera facial mask which represents loyalty, courage and righteousness in Peking opera. It has a bright and eye-catching appearance, highlighting the regional cultural characteristics of Beijing.

The TBM industry usually classifies a TBM with a diameter of 12 m and above as a mega-sized TBM. The mega one integrates sophisticated technologies like mechanics, electric, hydraulic, information, sensing and optics, requiring extremely high reliability of the equipment. Having relied on the previous experience in designing, processing and manufacturing of conventional diameter TBMs and large-diameter TBMs and their key components and developing system integration technologies, CRCHI’s R&D team overcame the difficulties and developed this 16 m slurry TBM.

The Beijing East 6th Ring Road Reconstruction Project is a 16-km-long road between the Beijing-Harbin Expressway and the North Luyuan Avenue, including a widened section and a tunnel section. There are 2 tunnels on the main line, totaling 9,160 m, of which a 7,338 m is constructed using mechanized shield machine. Its complex geology is mainly composed of sandy soil, water-rich and high-density sand, interactive layers of silt and cohesive soil. The project faces construction difficulties, such as super-large excavation diameter, super-long distance, super-deep overburden and complicated geological conditions.

In this regard, this slurry TBM is equipped with a number of core technologies like free air cutter change, telescopic main drive, handling of heavy-duty segments, efficient and high-power slurry circulation system, and high-precision pressure balance control of the tunnel face. At the same time, innovations are made on the machine, such as segment ring convergence measurement, segment ring flatness detection, segment ring selection, automatic tailskin gap measurement, concurrent grouting of A+B components, slurry pipe extension system with three-way blocker, which guarantee a safe, high efficiency and green construction.

Since July 2020, CRCHI has manufactured two mega 15m-diameter slurry TBMs which will be used in the construction of Genshan Road and Xiasha Road tunnels in Hangzhou, China. Another 15 m slurry TBM is being manufactured, which will be used in the construction of crossing river passage in Changsha, China.