The reporter learned from Qinghai Provincial Communications Control Group that on the morning of January 3, the right tube of Xiangcao Tunnel on the Ledu-Hualong Expressway in Qinghai Province (hereinafter referred to as Lehua Expressway) was successfully holed through. At this point, both tubes of the tunnel have been fully connected.

It is reported that the Xiangcao Tunnel is the second tunnel on the Lehua Expressway to be holed through, following the Yaocaotai Tunnel. The Xiangcao Tunnel has a total length of 2,560 meters and adopts a separated double-tube structure with a design speed of 80 kilometers per hour. The tunnel site area consists entirely of Grade V surrounding rock, mainly gravelly soil and strongly to moderately weathered tuffaceous sandstone. The surrounding rock has poor stability, making construction difficult and safety risks high.

The Lehua Expressway is located in Ledu District and Hualong County of Haidong City, Qinghai Province. It is part of the planned G213 national highway and also an important component of the "three vertical" lines in the "three vertical and three horizontal" external comprehensive transportation corridors of the eastern Qinghai urban agglomeration.

During construction, the project closely centered on the general requirements of building a "Safe Century Quality Project," adhered to the guidance of scientific and technological innovation, and upheld the concept of "mechanization replacing manpower and automation reducing personnel." It applied fully mechanized supporting operation equipment for the entire process, including arch installation trolleys, wet spraying robotic arms, inverted-arch hydraulic trestles, and waterproof board hanging trolleys, and was equipped with information-based and intelligent facilities such as real-name personnel registration for tunnel entry, video monitoring, and automatic fan frequency control systems. At the same time, it strictly implemented the construction principles of "advance pipe roof support, short advance, weak blasting, strong support, rapid sealing, and frequent measurement," adopted means such as advanced geological forecasting and surrounding rock monitoring and measurement, and carried out dynamic demonstration and optimization of the construction plan, so as to advance safety, quality, and progress in parallel and ensure the smooth holing-through of the tunnel and the achievement of construction goals on schedule.