After 32 months, the Jigongzhai Tunnel, a controlling project of the Baoyi section of the Shiwu Expressway, was holed through on the afternoon of January 28, marking the full connection of the Baoyi section invested and built by Hubei Communications Investment Group, with the project now entering its final sprint and wrap-up stage.

　　This afternoon, with the successful completion of the final blast, the right tube of the 4,878-meter Jigongzhai Tunnel was officially broken through, the last holing-through point among all 14 tunnels on the route. As the controlling project and the longest tunnel of the Baoyi section of the Shiwu Expressway, the holing-through of the Jigongzhai Tunnel marks the full connection of the Baoyi section, laying the foundation for the rapid advancement of asphalt paving and ancillary works across the entire route.

　　The Jigongzhai Tunnel area features complex terrain with many deep “V”-shaped valleys, and the maximum buried depth of the middle section is about 460 meters. The entire tunnel consists of sericite quartz schist, a soft rock, and 75% of it lies in an extremely high in-situ stress zone, posing a great risk of deformation. During construction, advanced techniques and equipment such as anchor drilling rigs, wet-spraying manipulators, shaped-charge water-pressure smooth blasting, formwork grouting for lining, gallery ventilation and fog cannon dust removers were adopted, successfully passing through one major fault, two fracture-affected zones and eight geological anomaly areas to achieve smooth holing-through, creating favorable conditions for the route to be completed and opened to traffic in the first half of this year.

　　The Baoyi section of the Shiwu Expressway starts in Baoxia Town, Yunyang District and ends in Yishui Town, Zhushan County, with a total length of 58.632 kilometers, including 53 bridges totaling 29,527.81 meters and 14 tunnels totaling 16,830 meters, with a bridge-tunnel ratio as high as 79.6%. The project started construction at the end of May 2018, with an approved budget estimate of 10.211 billion yuan. Up to now, 98.2% of the total investment has been completed, including 99.5% of bridge works, 99.1% of tunnel works, 62.8% of pavement works, 97% of building works, 56% of traffic safety works and 52% of electromechanical works.

　　As an important part of the “Vertical Line 8” of the “nine vertical, five horizontal and three ring” expressway network planned by Hubei Province, the construction of the Baoyi section of the Shiwu Expressway is of great significance for improving the layout of the national expressway network, optimizing the expressway network structure in the Hubei-Henan-Shaanxi border area, improving traffic conditions in the Qinba Mountain area, driving the development and utilization of distinctive resources along the route, and boosting the economic and social development of northwestern Hubei and surrounding areas.