Recently，The smallest hard rock roadheader in China built by China Railway Construction Heavy Industry and China Railway 18th Bureau“Water source number”Break through the rock，It marks the successful completion of the water conveyance tunnel of the Mabai branch line of the water resources allocation project in the downtown area of Shiyan City.，It laid the foundation for the smooth water supply of the project.。

“Water source number”TBMThrough the site

As the No.1 livelihood project of Shiyan City，The water resources allocation project in the central urban area of Shiyan takes Pankou Reservoir in Zhushan as the water source.，New headrace tunnel to Majiahe Reservoir，The total length of the diversion line is more than 70 kilometers.。Among，Tunnel 5 Outlet Section 15.367 kilometers、Majiahe-Baierhe Reservoir Branch Line 4.Construction task of 155 km，Developed by Railway Construction Heavy Industry Co., Ltd.“Wudang”“Water source number”2 Tunnel Boring Machines（TBM）Synchronous construction。

The total length of the diversion tunnel of Mabai branch line is 4155 meters.，To avoid the traditional“One-way tunneling drilling and blasting technology”Impact on the surrounding environment，Builders according to the actual situation，Innovative manufacturing“Water source number”TBMProceed“Minor surgery”——For the first time in China, the tunnel boring machine with ultra-small diameter has been used in tunnels.。

As the smallest hard rock roadheader in China,，ThisTBMAbout 60 meters long、Excavation diameter is only 2.5 meters，It is equipped with automatic tunneling intelligent function.，The operator can realize the remote operation and control of the whole machine outside the tunnel.。Successful application of the device，It has greatly promoted the mechanization of tunnels with small cross sections.、Development of automated and intelligent construction。

“Water source number”TBM

“Water source number”TBMArrive at the project construction site on September 15, 2021，It only took more than 10 days to complete.TBMAssemble and start tunneling。After the equipment is put into use,，Excavate about 10 meters every day，It is 3 to 6 times more efficient than the drilling and blasting method，While speeding up the pace of construction,，Further reduces security risk，Improve the level of safety management，It has won time for the early completion of the Baier River ecological restoration project.。

“Based on the long distance of the tunnel of Mabai branch line of the water resources allocation project in the central urban area of Shiyan City、Small section, etc.，We're in the process of digging.，Overcome the microTBMThe design of the cutter head is difficult、Difficult slag tapping of main machine、Difficult arrangement of equipment space、Long-distance rail transportation and other difficult problems，It has achieved an average monthly footage of 200 meters.，Created‘Maximum daily footage 23.68 meters、Maximum monthly footage 343.38 meters’A miniatureTBMConstruction records。”The project leader introduced.。

Schematic Diagram of Water Resources Allocation Project in Shiyan Central District

It is reported that，The project mainly supplies water for urban life and industry in the downtown area of Shiyan City.，Through the return of ecological water，Optimize the water use conditions and water ecological environment in the receiving area，To create conditions for improving the ecological environment of the urban section of the Baier River，Will benefit 74.70,000 people。