On October 20, with the right tunnel of Shangluo Tunnel running through, the longest tunnel of the Sichuan Yibin to Yunnan Weixin expressway, which was constructed by the China Railway No.5 Engineering Group, was completed eight months ahead of schedule.
Located in Gongxian County, Yibin City, Shangluo Tunnel is designed as a two-way four-lane tunnel with a left tunnel length of 7066 meters (through September 29 this year) and a right tunnel length of 7032 meters. The tunnel site is located in a karst development area with poor topographic conditions and complex geological conditions and is prone to rock bursts, water gushing, and other adverse geological conditions during construction. The surrounding rock of the whole tunnel is horizontally thin, and the risk of vault collapse and block falling is high, which belongs to the high-risk tunnel and is the key control project of the whole line.
Faced with the complex geological conditions, the project department of the China Railway No.5 Engineering Group has been adhering to the spirit of "trailbreaker" since its construction started in May 2020, carefully organizing and scientifically constructing, and by the construction principles of "early prediction, pre-reinforcement, less blasting, short footage, strong support, early closure, frequent measurement, and fast lining". One inclined shaft and one horizontal tunnel were opened, and six working faces were added, which solved the problems of ventilation and smoke exhaust, transportation, and reverse slope drainage in the extra-long tunnel, overcoming adverse factors such as bad geology, high temperature, and frequent earthquakes, and realized the smooth penetration of the tunnel ahead of schedule on the premise of ensuring the construction quality and safety.
It is understood that the Yiwei expressway is one of the seven new channels planned for Sichuan Province. The project starts at the Shuanghe Hub Interchange on the expressway around Yibin and ends at Banzhuwan. After the project is completed and opened to traffic, it will play an important role in building the economic sub-highland in southern Sichuan and promoting the economic and social development of Yibin City and the Sichuan-Yunnan-Guizhou junction area.
