Recently, the Pipawan Tunnel in the sixth contract section of the Guanxin Expressway achieved two-way breakthrough, marking the successful completion of an important construction milestone for the Guanxin Expressway and new progress in the project construction.

It is reported that the Pipawan Tunnel has a total length of 256 meters, including 145 meters of Class IV surrounding rock, 95 meters of Class V surrounding rock, and 10 meters of open-cut tunnel. The surrounding rock is mainly gravel and strongly to moderately weathered sandy slate, with broken rock mass, poor self-stability of surrounding rock, and relatively complex geological conditions. As tunnel construction faced many unfavorable factors such as complex geological conditions, difficult material transportation, a long rainy season, and limited power resources, the project department actively applied new technologies, new processes, and new equipment to overcome difficulties encountered during tunnel excavation, such as tunnel face collapse and surrounding rock turning into mud upon contact with water, ensuring project quality and safety and balanced and controllable construction progress.

A person in charge of the Guanxin project introduced that the project has a total of 22 tunnels, including 25,605 meters/20 tunnels on the main line (7,835.5 meters/2 extra-long tunnels) and 1,495 meters/2 connecting line tunnels. The two-way breakthrough of the Pipawan Tunnel is only one of the milestones in advancing the project construction. This year, apart from the key control projects of the Malukou Zishui Grand Bridge and the Huangshajie Tunnel, efforts will be made to achieve half-width through traffic for the entire project by the end of the year.

The Guanzhuang至Xinhua Expressway in Hunan Province is an important component of the “Hohhot至Beihai National Expressway G59”, one of the 165 major engineering projects of the national “13th Five-Year Plan”, and also a key national poverty alleviation project. The project starts at Muzhuopu, Guanzhuang Town, Yuanling County, connects with the G59 Zhangjiajie至Guanzhuang Expressway, and ends at Shuikoukeng, Langtang Town, Xinhua County, connecting with the Xinxu Expressway. The main line has a total length of 76.581 kilometers, with a total estimated investment of 13.653 billion yuan.

The construction of the Guanxin Expressway is of great significance for improving the national and Hunan provincial expressway networks, developing regional tourism resources, and promoting the economic and social development of the areas along the project and even the entire province.