Large diameter pipeline construction practices in steep slope tunnel

Taking the DaXiLiang steep slope tunnel section in the mountainous section of Sichuan-East Gas Pipeline Project as an example, the technical difficulties of large diameter pipeline construction in steep slope tunnel have been summarized and concrete construction schemes and key technologies have been put forward too. Construction sequence is that the civil construction is made prior, and pipeline installation and construction follow it. Considering the demands of single pipe transportation and the constraints of natural conditions, the pipeline installation has been executed from the top to bottom of the steep slope. The hoister with transducer can provide the power in single pipe's transportation, and special railway car is used to convey the pipe. Pipe unloading and pipe string in the construction process have been done by using combination chain block shelves, and the hoister have been used to provide traction power. All the techniques are derived from the practice, with good feasibility and practicality.