On April 12th, the 14.02-meter large diameter CRCHI TBM named 'New Crossing' successfully completed its Lot II tunnel section, by tunnelling the Shanghai airport link line for the first municipal railway.

The Shanghai Airport Link Line Lot II is the key control engineering of the whole line, with a shield machine tunnel length of 4939.8m and a single tunnel for double track design. The Lot II is now the first large diameter shield machine tunnel in China with a long distance and small spacing paralleling with a high-speed railway line in operation. The minimum distance between the tunnel and the Shanghai-Hangzhou High Speed Railway is only 8.1m, and the construction also involves crossing under important structures several times such as municipal highways, railways and bridges.

As per the characteristics of the project, 'New Crossing' was equipped with a number of key technologies such as normal pressure soft soil cutterhead, a high pressure resistant main drive seal, efficient material transportation and synchronous assembly for prefabricated structure, which greatly improved the adaptability and reliability of the shield machine. At the same time, with intelligent monitoring systems, the average daily advancement of the TBM reached 10.4 meters. The maximum monthly advancement reached 576 meters, and monthly advancement exceeded 400 meters for six consecutive months.

The Shanghai Airport Link Line is the first time China has adopted a fully prefabricated structure assembly system, pioneering a similar construction methodology in China. Faced with the requirements of a large volume of prefabricated components, the large size of single components, high precision requirements of installation and the difficulty of assembly, CRCHI developed a fine adjustment system for box culvert and isolated wall assembly equipment in China, realizing the intelligent one-key assembly from automatic grasping to precision control of the full prefabricated box culvert and isolated wall under the track. The highest record for the installing of the isolated wall in a single month was 1200m, which set the record of the fastest assembly in the whole line. For further information about CRCHI and its products please visit their website en.crchi.com. 21/23.