The Chongtai Yangtze River Tunnel of the Shanghai Chongqing Chengdu High speed Railway, constructed by China Railway Group, has achieved critical progress. The world's largest diameter high-speed rail shield machine, independently developed by China, has successfully reached the No. 2 vertical shaft on the south bank of the Yangtze River. The Chongtai Yangtze River Tunnel Navigation Ship has successfully crossed the Yangtze River water area, setting a new world record for the continuous excavation of 11.325 kilometers by a 15 meter large-diameter shield machine alone.

The diameter of the cutterhead of the Navigation shield machine reaches 15.4 meters and is equipped with an I-TBM intelligent control system, which can achieve millimeter level linear control. In addition, the Qiming, which completed the excavation of the 2nd vertical shaft, is the world's largest diameter vertical shaft boring machine, with an excavation diameter of 24 meters and a depth of 56.08 meters.

The Chongtai Yangtze River Tunnel is a key control project of the Shanghai Chongqing Chengdu high-speed railway, connecting Chongming in Shanghai and Taicang in Jiangsu. It has a total length of 14.25 kilometers and integrates five super construction conditions, including ultra long distance, ultra large diameter, ultra high speed, ultra deep pressure bearing, and ultra large vertical shaft. It is currently the highest construction standard and largest scale high-speed railway cross river tunnel project in China. The project team innovatively applied construction technologies such as intelligent perception, intelligent prefabrication, intelligent excavation, and intelligent control to build a multi-layered protection system that integrates sealing, grouting, and intelligent monitoring. It successfully crossed major risk areas such as the Yangtze River embankment, main waterway, and the national level aquatic germplasm resources protection zone for the catfish, and passed through the deepest part of the river at 89 meters.

After the completion of the Chongtai Yangtze River Tunnel, it will end the history of Chongming Island not being connected to high-speed rail. It only takes 17 minutes to travel from Chongming to Baoshan in Shanghai via Taicang.

This article is reprinted from: China Railway Engineering Group Co., Ltd       Editor/Gao Xue