China's Largest Diameter TBM Exported Overseas Plays Role in Jakarta-Bandung High-Speed Railway Tunnel Construction

The No. 1 tunnel of the Jakarta-Bandung high-speed railway in Indonesia was dug through on Nov 24 thanks to China's largest diameter tunnel boring machine (TBM) ever exported overseas.

The Jakarta-Bandung high-speed railway is the first with a maximum speed of 350 kilometers per hour in Southeast Asia and is an icon of the Belt and Road Initiative and Indonesia's Global Maritime Fulcrum strategy.

The construction condition of the No. 1 tunnel is extremely complicated, which exaggerates the project's construction difficulties and risks.

The 1,469-meter tunnel is being built through a mixture of cohesive soil, gravel, sandy soil and fine gravel that has a high underground water level and abundant surface water. It has to pass through a volcanic accumulation layer, with poor self-stabilization capacity.

What's worse, the tunnel goes under build-up areas, the only highway to travel out of Jakarta and its ramps as well as two mosques.

The 2,600-ton TBM with a 13.19-meter-diameter and 101-meter-long cutter was designed and developed by Tianhe Mechanical Equipment Manufacturing Co., Ltd., a subsidiary of China Communications Construction Company Limited, in response to the complicated geological conditions.

Such internationally-leading technologies as subsidence control, stratified backwash, a cutter with long duration and real-time tool wear monitoring were used on the machine.

During the tunnel's construction, the TBM had set a record of digging 320 meters a month amid the COVID-19 epidemic, a result of builders' efforts to maintain equipment and high-quality engineering.

Once operable, the 142-kilometer railway will shorten travel time between Jakarta and Bandung to 40 minutes. It will promote construction of the Trans-Asian Railway network and effectively relieve traffic congestion between the two cities.

In addition, it is expected to play a role in forming the Jakarta-Bandung economic corridor and boost Indonesia's economic and social development.

A view of the 13.19-meter-diameter slurry balance TBM used in construction of the No. 1 tunnel of the Jakarta-Bandung high-speed railway in Indonesia [Photo/sasac.gov.cn]

The cutter of the TBM is hoisted to go down the well. [Photo/sasac.gov.cn]

A ceremony is held on Nov 24 to celebrate the digging through of the No. 1 tunnel of the Jakarta-Bandung high-speed railway. [Photo/sasac.gov.cn]

(Executive editor: Wang Ruoting)