Linghang, the world’s largest-diameter shield tunneling machine, tailored for high-speed railway construction and developed domestically in China, successfully bored its way through an underwater tunnel traversing the Yangtze River on July 30. The achievement set a new world record for a single continuous drive of 11.325 kilometers by a shield tunneling machine with a 15-meter-level diameter.
The machine successfully reached the No 2 shaft at the southern bank of the Yangtze River, which is a component of the Chongming-Taicang Yangtze River Tunnel undertaken by China Railway Group Limited.
Linghang has a cutter head with a diameter of 15.4 meters and is equipped with the I-TBM intelligent control system, enabling millimeter-level alignment control. In addition, the No 2 shaft, at a diameter of 24 meters and a depth of 56.08 meters, was excavated by the world’s largest-diameter shaft boring machine, Qiming.
The 14.25-km-long cross-river tunnel, a crucial project of the Shanghai-Chongqing-Chengdu High-speed Railway, connects Chongming District in Shanghai with Taicang, a county-level city in Jiangsu Province. The tunnel presents five “ultra” construction challenges: ultra-long distance, ultra-large diameter, ultra-high speed, ultra-deep pressure and ultra-large shafts, making it China’s largest cross-river tunnel project for high-speed railways. Because of those challenges, the project must meet the highest construction standards.
To address these issues, the project team innovatively applied a series of intelligent construction technologies on perception, prefabrication, tunneling and management, and established a multi-layered protection system integrating “sealing, cement pouring and intelligent monitoring”. This enabled the tunnel to successfully traverse high-risk areas such as the Yangtze River dike, main navigation channel and the National Aquatic Germplasm Resources Conservation Area for Coilia nasus, as well as the deepest point of the entire construction project — 89 meters beneath the riverbed.
Upon completion, the tunnel will extend the high-speed railway to Chongming Island for the first time, reducing the travel time from the island via Taicang to Baoshan, another Shanghai district, to 17 minutes.
(Executive editor: Zuo Shihan)
