On January 18, construction officially began on the east tunnel of the Huanghua Airport section of the newly built Changsha–Ganzhou Railway, marking that the Changsha Airport expansion and renovation project has entered the fast lane and that new progress has been made in the construction of the new Changsha–Ganzhou Railway.

The starting point of the Huanghua Airport Tunnel on the newly built Changsha–Ganzhou Railway is located at the east end of the Huanghua Airport Station of the high-speed rail comprehensive transportation hub of the Changsha Airport expansion and renovation project, and the end point is located at the east end of the land acquisition red line of the Changsha Airport expansion and renovation project, with a total length of 673.57 m. The tunnel is a single-tube double-track tunnel designed for a speed of 350 km/h. The tunnel body is basically located in weakly weathered argillaceous siltstone and will be constructed by mechanical excavation, with an estimated 110,680 cubic meters of earth and rock to be excavated and transported out.

General layout plan of the Changsha Airport expansion and renovation project

Comprehensive transportation planning diagram of the Changsha Airport expansion and renovation project

According to reports, the main geology of the tunnel consists of artificial fill, alluvial-proluvial deposits, mucky clay, silty clay intercalated with clay, argillaceous siltstone, and so on. The tunnel body is located in extremely soft rock argillaceous siltstone, and the stability of the tunnel body is relatively poor. To ensure safe and smooth construction of the tunnel, the principles of "short advance, strong support, early closure, and frequent measurement" are adhered to during excavation, mechanical excavation technology is adopted, the advance per cycle is no greater than one support spacing, and the construction quality of processes such as pipe roof, small conduit, and anchor bolts is strengthened; during the upper bench stage of the excavation face, before each ring of advance support construction, when the stability of the excavation face is poor or groundwater is developed, the excavation face is sealed by spraying concrete to a thickness of 8 cm, reducing the impact of water leakage on soil stability.

The Huanghua Airport section of the newly built Changsha–Ganzhou Railway is an important component of the Changsha Airport expansion and renovation project, an important component of the Xiamen–Chongqing corridor, one of the "eight vertical and eight horizontal" corridors of the national high-speed railway network, and an important passenger dedicated line in the national "14th Five-Year Plan" railway development plan. The Changsha–Ganzhou Railway will effectively improve the regional transportation infrastructure conditions along the line, enhance economic ties and personnel exchanges between the areas along the line and developed regions such as the Guangdong–Hong Kong–Macao Greater Bay Area and the West Taiwan Strait Economic Zone, and is of great significance for promoting coordinated regional development, narrowing the development gap between the eastern and central regions, consolidating and expanding the achievements of poverty alleviation, and implementing the rural revitalization strategy.