On September 26, the super-complex stratum large-diameter long-distance pipe jacking machine "Jiangyuan Jiaoliu," jointly developed by CRCC Heavy Industry and Sinohydro Bureau 5, completed a single jacking run of 946 meters, helping the Jiaoliu River diversion tunnel of the Yinchao-Jiliao Water Diversion Project achieve successful breakthrough.

The project set a domestic record for the longest pipe jacking run in extremely complex geology and high-water-pressure strata. It is also another outstanding achievement for CRCC Heavy Industry's pipe jacking equipment following the domestically largest-diameter pipe jacking machine "Tiejun." This marks a breakthrough success for pipe jacking machines in the construction of tunnels under complex conditions in large-scale water diversion projects in China.

The project used pipes with an outer diameter of 4.3 meters, with a single crossing distance of 946 meters and a maximum burial depth of 26 meters. The strata were extremely water-rich, and the water pressure throughout construction exceeded 2 bar. Rock layers, muddy gravel, and clay strata alternated frequently along the entire section, and the strata were soft at the top and hard at the bottom. Construction in such strata was like navigating through "waters full of hidden reefs." How to achieve a safe, efficient, one-pass successful jacking crossing was a challenge facing both the construction team and the equipment.

In response to the project's engineering characteristics and construction difficulties, the "Jiangyuan Jiaoliu" adopted a high-reliability design throughout. It was equipped with a heavy-duty hard-rock main bearing, a high-power-density main drive, an intelligent monitoring and control system, and an independent manlock, giving it the capability to handle various complex conditions. During construction, workers repeatedly used the independent manlock to enter the chamber under pressure in unstable strata for maintenance and cutter replacement. The equipment's powerful configuration and high stability ensured the project's successful breakthrough and achieved outstanding results of a maximum daily advance of 15 meters and a maximum monthly advance of 219 meters.