May 7th
The longest spiral tunnel in China
Xizhao Expressway Laoyingpan No. 1 Tunnel was completed
So far
It took 1,155 days of construction
All 3 tunnels of the Lo Ying Pun Tunnel Cluster have been broken through
Another control project of Xizhao Expressway was overcome
Xizhao Expressway, connecting Zhaotong City, Yunnan Province and Xichang City, Sichuan Province, has a total length of 184.8 kilometers, including 16.7 kilometers of the common line section of the Yangtze River Expressway, 168.1 kilometers of new construction, and the whole line adopts the standard construction of four-lane expressway, with a design speed of 80 kilometers per hour.
It is understood that the Laoyingpan tunnel group of Xizhao Expressway is located in the alpine valley area of Jinyang County, Liangshan Prefecture, Sichuan Province, which is known as the meeting place of "two provinces and three counties of Jiming". The design longitudinal slope of the tunnel group is 25‰, the minimum curve radius is 970 meters, the straight line distance between the entrance and exit is only 1.6 kilometers, and the height difference reaches 213 meters.
It is reported that under the construction of the Laoyingpan spiral tunnel group, the 1.05-kilometer-long No. 2 tunnel and the 1.24-kilometer-long No. 3 tunnel have been broken through on April 7, 2024 and December 30, 2023 respectively. The No. 1 tunnel is 5.1 kilometers long, which is the longest spiral tunnel under construction in China.
The Laoyingpan tunnel group is located in the Hengduan Mountains in southwest Sichuan, with steep terrain and canyons, and the tunnel entrance is located on the cliff, which is prone to collapse, landslide and debris flow, and has great safety risks. The tunnel passes through complex geological conditions, belongs to the thousand rock strata, the rock is extremely broken, the initial support is easy to deform and crack under the condition of high buried depth, and the tunnel is also faced with karst, fault, mud outburst, water gushing, rockburst, large deformation and other bad geology, and the construction is difficult.
As an expressway connecting Zhaotong City in Yunnan Province and Xichang City in Sichuan, Xizhao Expressway is of great significance for accelerating local social and economic development.
Source: Yunnan release
Audit|Ni Na
Editor|Wang Kai
Platform contact information|0870-2153979