CHONGQING (CQNEWS) -- Chongqing's rail transit not only goes through steep mountains and residential buildings but also runs across the mighty Yangtze River! The section between Chongqing Station and Nanbin Road Station of Chongqing Rail Transit (CRT) Line 27, which is under construction, will be a tunnel running across the Yangtze River and connecting Yuzhong District with Nan’an District. It’s the first cross-river tunnel of Chongqing Rail Transit.

What are the features of this underwater tunnel? How is it built? Let us find the answers with the reporter.

With a total length of 49 kilometers, Line 27 starts at Bishan Station in the west and ends at Chongqing East Station in the east, including 14 stations. China Railway Group Limited is responsible for the civil work of Section II of Line 27, which covers 18.56 kilometers in length and a total of four stations and six intervals.

The Chongqing Station-Nanbin Road Station section of Line 27, a tunnel running across the Yangtze River, is one of the critical projects of the construction of Line 27.

The section between Chongqing Station and Nanbin Road Station of Line 27 is 3.2 kilometers long, of which the cross-river tunnel is about 800 meters long.

The construction of an underwater tunnel is much more challenging than that of a conventional tunnel. The tunneling of Line 27 faces difficulties brought by mudstones, sandstones, sand-shale interlayers, fracture development, high water pressure, groundwater seepage, and other technical problems. Considering the above issues, the builder has decided to use the shield tunneling method.

Line 27 has accelerated the construction of its shield launching shaft in Changbin Road, Yuzhong District. Shield machines will start tunneling across the river from this underground shaft.

At the construction site, we can see that excavators, drilling rigs, and other equipment are working to excavate the rock and soil, and steel frames and reinforcement are used to reinforce the shaft. The excavated areas of the shaft have reached 68 meters in height. It is expected that shield machines will start tunneling from the shaft this year.

On its completion, Line 27 will link Chongqing East Station, Chongqing Station, and Shapingba Station, drive the development of business districts and residential areas along the line like Shapingba, Daping, Nanping, Chaoyuan, and University Town, and improve the efficiency of CRT. (Translated by Yuki, Fathom Language Limited)