On October 29, the right tube of the Shuangjiao Tunnel on Section 7 of the Yangjiang–Xinyi Expressway project, constructed by China Railway No. 4 Engineering Group under the investment and development of Guangdong Yangxin Expressway Co., Ltd. of China Railway Southern Investment Group, was successfully holed through 32 days ahead of schedule, becoming the first tunnel on the Yangjiang section of the Yangxin Expressway to be completed. This marks a breakthrough in the project's construction and production and lays a solid foundation for the expressway to open to traffic on schedule.

The Yangxin Expressway is a component of the "seven horizontal" corridors in the main skeleton layout of Guangdong Province's expressway network, known as "twelve vertical, eight horizontal, two ring and sixteen radial" routes. The route has a total length of approximately 142.2 kilometers, of which the Yangjiang section is 64 kilometers long. The 12.058-kilometer Section 7 of the Yangxin Expressway undertaken by China Railway No. 4 Engineering Group is designed for a speed of 120 kilometers per hour with six lanes in both directions. Its main construction content includes tunnels, bridges and roadbed works, and it is scheduled to open to traffic on June 30, 2025.

The concealed section of the right tube of the Shuangjiao Tunnel holed through this time has a total length of 614 meters and is designed as a three-lane tunnel. It is characterized by a large construction cross-section, shallow cover and poor stability of the surrounding rock. The portal section is constructed using the double-side-drift method, which involves great operational difficulty and high safety risks. To ensure the smooth holing-through of the tunnel, the contractor, China Railway No. 4 Engineering Group, strictly carried out excavation operations in accordance with the principles of "advance pipe forepoling, strict grouting, short excavation, strong support, early closure and frequent measurement," ensuring that every procedure was monitored by dedicated personnel. It also established a smooth blasting leading group and a technical research group, strictly abiding by the "six fixed" principles of smooth blasting—"fixed personnel, fixed drilling rigs, fixed locations, fixed quantities, fixed times and fixed responsibilities." During the process, additional technical personnel were dispatched to the site for technical guidance and process supervision, effectively controlling overbreak and underbreak in the tunnel and improving the quality and efficiency of tunnel excavation. In terms of safety management, the project department adopted a personnel trajectory access control system at the tunnel portal to track the dynamics of personnel inside the tunnel in real time, and implemented tiered safety control within the tunnel to ensure that tunnel construction safety remained under control at all times.

The Yangxin Expressway is an important corridor connecting the Beibu Gulf of Guangxi and central western Guangdong to the Guangdong-Hong Kong-Macao Greater Bay Area and eastern Guangdong, and is also a key project in Guangdong Province's efforts to improve its transportation infrastructure. Once completed and opened to traffic, the project will be of great significance for improving Guangdong Province's expressway network, enhancing the radiating and driving role of the Guangdong-Hong Kong-Macao Greater Bay Area for western Guangdong, improving regional transportation conditions and promoting coordinated economic development along the route.