Recently, cumulative excavation of the left tube at the entrance of the Zhongliangshan Tunnel in the Chongqing Yuwu Second Branch Project exceeded 2,000 meters, laying a solid foundation for the left line to be holed through before the end of the year.

Construction site

The Zhongliangshan Tunnel is a controlling project of the entire Yuwu project. The tunnel is 5,310 meters long and is designed as a separated tunnel. The Yuwu Second Branch Project is responsible for the construction of 3,375 meters of the entrance left tube, 3,425 meters of the right tube, and a 1,100-meter inclined shaft section. The tunnel passes through unfavorable geological conditions such as shallow cover sections, coal seams, gas, karst caves, underground rivers, and mined-out areas, posing high construction safety risks and great technical difficulty.

During construction, the project team adhered to the construction principles of "early forecasting, water control first, advance pipe roof support, short advance, weak blasting, strong support, tight sealing, and frequent measurement," focused on the standardization of processes and techniques, promoted mechanized supporting operations for the tunnel, established an advanced geological forecasting and monitoring measurement information system, and conducted automatic monitoring of toxic and harmful gas concentrations such as ventilation and gas in the tunnel. Through multiple measures, they overcame a series of construction difficulties, including blasting for construction involving railways, fault fracture zones, mud and water inrush geological disasters, and gas prevention and control, advancing the overall construction progress safely and efficiently. As of now, 826.4 meters remain in the left line of the Zhongliangshan Tunnel.

The Chongqing-Wuhan Expressway double-track project starts at the Caijia Interchange in Beibei on the G75 Lanzhou-Haikou Expressway and ends at Fengmu Village, Caojie Subdistrict, Hechuan District. It has a total length of 35.53 kilometers and a bridge-tunnel ratio of 58%. Once completed, the project will connect multiple east-west corridors in Chongqing's central urban area and will promote and facilitate the construction of the Chengdu-Chongqing economic circle.