Recently, according to Guangzhou Communications Investment Group, with the completion of the final pour of the four-lane secondary lining structure, the Shimentangshan Tunnel expansion project has achieved another major engineering milestone—the main structure of the 670-meter single-tube, four-lane ultra-large-span tunnel has been successfully completed. It is reported that the overall construction schedule of the tunnel expansion project has been advanced by 9 months, and it is expected to be completed and opened to traffic before National Day.

The Shimentangshan Tunnel expansion project on the South China Expressway starts at the Xiyang Bridge north of the Shimentangshan Tunnel on the South China Expressway and ends at the north side of the existing Jinji No. 1 Medium Bridge on the South China Expressway, with a total length of about 2.0 kilometers, including one new bridge and one new tunnel. On April 29 this year, the newly built Shimentangshan Tunnel project on the South China Expressway was holed through, achieving the phased goal half a year ahead of schedule.

The newly built Shimentangshan Tunnel is the first ultra-large-span tunnel in China to be built alongside an existing double-arch tunnel. In order to solve problems such as the poor stability of Class V surrounding rock at the portal section of the large-span tunnel construction and construction adjacent to the existing tunnel, the municipal project department conducted risk assessments and, on the premise of fully ensuring construction safety, accelerated the construction speed and completed important engineering milestones, providing an important guarantee for the project to be completed and opened to traffic as scheduled.

The Shimentangshan Tunnel expansion project on the South China Expressway is a key implementation project for congestion relief in the Shimentangshan section of the South China Expressway. According to traffic volume data in recent years, the northbound Shimentangshan Tunnel has been congested for nearly 300 days a year.

After the new tunnel is completed, the original Shimentangshan Tunnel will be converted to two tubes with one-way traffic in each, forming a dual-direction, eight-lane configuration with the newly built Shimentangshan Tunnel, eliminating the traffic bottleneck and alleviating severe congestion in the Shimentangshan section of the South China Expressway, especially in the direction from central Guangzhou heading north out of the city.