“The Long March is a dangerous journey.，The most memorable Jiajin Mountain”。Jiajin Mountain is located in Aba Tibetan and Qiang Autonomous Prefecture of Sichuan Province.，It was the first big snow mountain crossed by the Red Army during the Long March.，The highest elevation is 4100 meters.。Jointly built by China Railway Construction Heavy Industry and China Railway 11th Bureau“Jiajinshan”Open hard rock tunnel boring machine（TBM）It is being excavated efficiently in this famous mountain peak.，The daily footage reached 50 meters on September 18.，Created our country's highwayTBMA new record of daily driving footage。

Construction site

Excavation diameter of Jiajinshan Tunnel 7.93 meters，The total length of the tunnel is 9.Four kilometers，With four、Five types of slate、Mainly sandstone，The arch frame is supported all the way，Arch spacing 0.9 meters，The construction is very difficult.。With the full cooperation of the on-site technical personnel of China Railway Construction Heavy Industry and the on-site construction personnel of China Railway 11th Bureau，“Jiajinshan”Since the start of excavation at the end of June 2022，Overcome the obstacles of harsh working conditions and the impact of the novel coronavirus epidemic，Make every effort to ensure the construction progress，At present, a total of 1054 meters have been excavated.。

  

《Sichuan News Network》Reports

National Highway 351 Jiajinshan Tunnel Project belongs to Sichuan Provincial Party Committee and Government“I do practical things for the masses.”A livelihood project、Key projects of the Provincial Communications Department，It is the longest second-class highway tunnel in China.。Opening the Jiajinshan Tunnel Will Change the Winter Closure of National Highway 351“Winter Tube”Limitations，It can pass all the year round.，Greatly reduce travel times，Greatly enhance the road disaster relief support capacity，To promote the development of red tourism resources along the line、It is of great significance to support the revitalization and development of the old revolutionary areas.。

  

“Jiajinshan”TBMOff the line

At the same time，“Jiajinshan”It is used for the first time in the construction of national and provincial trunk highways.TBMSuccessful cases of construction，It will also promote the wide application of similar products in secondary highway tunnels.。