By Lynda Myer
Following excavation of the Shanghai airport link line for the first municipal railway on April 12th, the New Crossing TBM with 14.02-meter large diameter successfully completed its Lot II tunnel section.
Involving a shield machine tunnel length of 4939.8m as well as a single tunnel for double track design, the Shanghai Airport Link Line Lot II is the key control engineering of the whole line. While it has a long distance and small spacing paralleling with a high-speed railway line in operation, currently the Lot II is the first large diameter shield machine tunnel in China. 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.
Providing normal pressure soft soil cutterhead, a high pressure resistant main drive seal, efficient material transportation as well as synchronous assembly for prefabricated structure, which greatly improved the adaptability and reliability of the shield machine, the TBM New Crossing is in accordance with the characteristics of the project. Additionally, using the intelligent monitoring systems, the average advancement of the TBM reached 10.4 meters per day, whereas the maximum monthly advancement attained 576 meters, and monthly advancement exceeded 400 meters for six consecutive months.
Considering that it is the first time that China has adopted a fully prefabricated structure assembly system, pioneering a similar construction methodology in China through advancing the Shanghai Airport Link Line, CRCHI encountered 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 and so 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. Being marked as the record of the fastest assembly in the whole line, the highest record for the installing of the isolated wall in a single month was 1200m. For further information about CRCHI and its products please visit their website.
