On June 11, 2022, the Pinggongshan Tunnel, the world's first high-speed railway tunnel with a speed of 350 kilometers per hour, was successfully completed. Lay the foundation for the construction of the follow-up beams and ballastless track of Shanshan-Shantou Railway.

Pinggongshan Tunnel has a total length of 1006.31 meters. It is located in Chikeng Town, Shanwei City. It crosses above the Pingfengshan Tunnel of the existing Xiamen-Shenzhen high-speed rail line. It is one of the key and difficult projects and control projects of Shantou-Shantou Railway.

Since the clear distance between the Pinggongshan tunnel and the operating Xiamen-Shenzhen high-speed railway tunnel is only 16.545 meters, it is difficult to carry out blasting construction. It is finally determined that the electronic detonator differential control blasting scheme is used in the affected section of the upper span using the time of the existing skylight, and the control vibration speed is not greater than 1.5 cm/sec. During the construction period, the tunnel has been blasted 77 times in total for the skylight points, and the blasting and excavation task of 97.6 meters has been safely completed.

In order to further reduce the impact on the safety of the existing tunnel structure and speed up the construction progress, the project adopts a combination of micro-vibration and micro-difference control blasting + mechanical excavation for excavation, making every effort to minimize the impact of the construction on the existing tunnels and ensure the existing tunnels. While the tunnel is safe, the construction efficiency is improved, and the safe and orderly passage of the Pinggongshan Tunnel is guaranteed.Editor/Ma Xue