At 9:30 on September 12, with the completion of the final blasting operation, the Shentongshan Tunnel of Section 2 of the Lairong High-Speed Railway, constructed by China Railway No. 4 Engineering Group, was successfully holed through. This is the first tunnel on the entire Lairong High-Speed Railway to be completed, marking a new breakthrough in the project's tunnel construction and laying a solid foundation for ensuring the smooth operation of the girder-erection passage at the Haiyang East Girder Fabrication Yard and for the next stage of girder-erection construction.

The Shentongshan Tunnel is located in Shirenpo Village, Haiyang City, and is designed as a double-track tunnel. The operating speed is 350 kilometers per hour. The tunnel is situated in an eroded hilly area, with a minimum cover depth of only about 2 meters, obvious changes in rock strata, and poor geological conditions.

In response to the problems of ultra-shallow cover and two crossings of fractured zones, the project department organized expert technical seminars and invited experts and professors from the owner unit, design unit, supervision unit, and the industry to conduct on-site exchanges and discussions on the construction plan, resulting in the implementation plan of advanced conduits and surface grouting. The project adopted the most advanced tunnel smooth blasting technology, invested in advanced equipment such as hydraulic invert trestles and intelligent lining trolleys, strengthened advanced geological forecasting and monitoring and measurement work, and strictly implemented the principles of "advanced pipe forepoling, strict grouting, short excavation, strong support, early closure, and frequent measurement," achieving comprehensive improvements in progress, safety, and quality and ensuring the successful breakthrough of the tunnel.

The ZQSG-2 project of the Lairong Railway undertaken by China Railway No. 4 Engineering Group is located in the southern coastal area of the Jiaodong Peninsula in Shandong Province, passing through Haiyang City of Yantai and Rushan City of Weihai, with newly built Haiyang Station and Rushan South Station. The line has a total length of 46.374 km, a design speed of 350 km/h, a contract value of 4.473 billion yuan, and a contract period of 42 months. After completion and opening to traffic, it will greatly optimize the layout of the railway network in the Jiaodong Peninsula region and is of great significance for improving the disadvantageous terminal position of the comprehensive transportation network in the Jiaodong Peninsula and promoting the integration of the Jiaodong economic circle.