Recently, the right tube of the Gongtong Tunnel, with a total length of 5,123 meters and constructed by the Bridge Group under Guizhou Communications Construction Group, has been fully and smoothly holed through. As of now, the main line of the Naqing Section 2 bid has achieved full holing through, providing favorable conditions for the subsequent entry of pavement, electromechanical and other works.

The Gongtong Tunnel is located in the Gongtong Nature Reserve in Nayong County. It is a separated extra-long tunnel and an important controlling project of the Naqing Expressway. It is jointly built by the Naqing T2 and T3 bids. The right tube is 5,123 meters long with a maximum burial depth of about 238 meters, and the left tube is 5,133 meters long with a maximum burial depth of about 248 meters. It presents various adverse geological conditions such as high gas and coal seam goafs. The strata along the tunnel alignment are relatively fractured, with Grade V surrounding rock accounting for more than 90%, resulting in great construction difficulty and high safety risks.

To ensure safe and orderly tunneling, during construction the Naqing Section 2 bid effectively prevented various risks through a series of measures including strengthening advanced geological forecasting, reasonable ventilation, establishing a gas monitoring system, gas drainage, and strengthening blasting management and hot work approval. The project department strictly implemented pre-shift education and technical briefings, controlled the construction process well, and ensured that construction quality met requirements.

The smooth holing through of the right tube of the Gongtong Tunnel has further aroused the enthusiasm and confidence of all construction personnel to work hard and fast. At present, only 100 meters remain in the left tube of the Gongtong Tunnel. Next, the Naqing Section 2 bid will continuously refine construction milestones, reverse the schedule, strengthen scheduling, focus on the site, race against time, and strive to sprint toward the completion goal.