CRCHI SPB Successfully Launched for the Construction of China’s First Cross-river Gas Pipeline


Project: Qianjiang-Shaoguan gas pipeline project

    On April 1st,2019, a CRCHI tunnel boring machine (TBM) for Sinopec’s first gas pipeline  was successfully launched in Yueyang of Hunan province. The pipeline is China’s first cross-river gas tunnel constructed by the Chinese TBM.
    The gas pipeline, as a main natural gas trunk line in south central China, will deliver natural gas of 6 billion cubic meters per year after it is put into use, which will ease the pressure of supply and demand on natural gas in Hunan and Guangdong province and play a key role in clean energy utilization and ecological civilization construction.

Project challenges:
   1.Only separate launching can be used as the launching shaft is small and deep.
   2.The TBM will tunnel through the Yangtze River and its embankment and under buildings.
   3.Very complicated geologies as the machine will tunnel through fracture zone,
   4.High water pressure and limited working space.

Equipment information: small-diameter slurry pressure balance shield machine (SPB, φ3800mm)

    Given that the geologies in the Yangtze River region are interbedding of silty clay and silt, deep silt, fully weathered argillaceous slate with strongly weathered rock, CRCHI R&D persons designed a composite cutterhead which is equipped with double-edge disc cutters to improve rock breaking capacity and a slurry circulation system for muck discharging.
    To apply to complicated geologies, the SPB is designed into two SPB modes which are direct control mode and indirect control mode. Two modes can be switched as required, ensuring safer and more efficient construction even in complex geohydrologic conditions.