On the morning of May 11, the final blasting operation was carried out for the newly built tunnel of the Tianmashan Tunnel Reconstruction and Expansion Project. The 1,075-meter-long new Tianmashan Tunnel achieved full breakthrough, 4 days ahead of the scheduled construction period.

"5, 4, 3, 2, 1, detonate!" On the morning of May 11, following an order from the commander, the final blasting operation was carried out for the newly built tunnel of the Tianmashan Tunnel Reconstruction and Expansion Project, and a rock mass about 2.4 meters thick shattered on cue. At this point, the 1,075-meter-long new Tianmashan Tunnel achieved full breakthrough. Next, electromechanical construction and installation and road surface work will be carried out inside the tunnel. It is expected to open to trial traffic on July 1, which will remove the traffic bottleneck between the urban area of Liuyang and the southern district.

At around 9 a.m. that day, the reporter saw at the site that the work of loading explosives in the tunnel had basically been completed, and the final blasting operation entered the countdown stage.

At 10:30 a.m., as the alarm sounded, temporary traffic control measures were implemented on the G319 Tianmashan Tunnel section, and construction personnel carried out the final safety inspection work in an orderly manner.

"Traffic control has been implemented, personnel in the tunnel have been evacuated, and blasting can proceed." After receiving the report, the on-site commander issued the "detonate" instruction.

After the blasting ended, Mr. Shi, a construction worker from Guandu Town, was the first to pass through the tunnel. He told the reporter that the blasting operation was very successful and the tunnel had achieved full breakthrough.

The Tianmashan Tunnel is located south of the Tianma Bridge on G319 and is designed as a single-tube, two-way, two-lane tunnel. With economic and social development, traffic volume gradually exceeded the original design capacity, and the number of lanes inside and outside the tunnel did not match, causing traffic to merge at the tunnel portal and often leading to traffic congestion. It became a major traffic bottleneck between the urban area of Liuyang and the southern district, causing great inconvenience to residents' travel.

To solve this problem, through the efforts of all parties, the Tianmashan Tunnel Reconstruction and Expansion Project was included in January 2019 in the Mid-term Adjustment Plan of the 13th Five-Year Development Plan for Transport in Hunan Province. As a major livelihood project, the 2019 Liuyang Municipal Government Work Report clearly proposed: accelerate the construction of the Tianmashan Tunnel Reconstruction and Expansion Project.

The G319 Tianmashan Tunnel Reconstruction and Expansion Project starts at the southern bridgehead of Tianma Bridge, extends southward along G319, and ends at the straight section of G319 near the east side of the Municipal Geriatric Rehabilitation Hospital. The route has a total length of 2.478 kilometers and adopts the technical standards of a Class I highway, with a design driving speed of 60 kilometers per hour. The newly added realigned roadbed has a width of 9.75 meters and includes one 1,075-meter tunnel. After completion, it will run parallel to the old tunnel and achieve two-tube one-way traffic, effectively alleviating traffic pressure while completely eliminating the safety hazards caused by single-tube two-way traffic.

At the end of 2019, construction started on the G319 Liuyang Tianmashan Tunnel Reconstruction and Expansion Project. "After work resumed following the epidemic, we reversed the construction schedule and adopted a 'monthly scheduling, weekly arrangement' working model to go all out and sprint, so the construction period was advanced and the tunnel breakthrough task was successfully completed," introduced Lin Yun, director of the Engineering Department of the Municipal Highway Construction and Maintenance Center. Since the project started, more than 300 blasting operations have been carried out, ultimately achieving the tunnel breakthrough 4 days ahead of schedule. Next, installation of electromechanical facilities and road surface construction in the tunnel will start immediately, with trial traffic planned for July 1. After completion acceptance, it can be officially put into use.