On the evening of October 25, accompanied by the roar of excavators, the first section of the foundation pit at the Hongxin section shield launching shaft station on Qingdao Metro Line 6, constructed by China Railway Shanghai Engineering Group, successfully "reached the bottom," marking that the station has officially entered the main structure backfilling and construction stage, accelerating the shield launching construction.

The shield launching shaft of the Hongxin section excavated this time is located in the municipal green space on the south side of Binhai Avenue, adjacent to the Qixin section of Line 6 Phase I to the east. It is a cast-in-place single-story underground box-frame structure. The foundation pit is about 52.8m long, 22.5-25.8m wide, and about 14-15.35m deep. The geological conditions are complex, with abundant coastal groundwater, rapid recharge, and strong permeability of the strata. During excavation, collapse and piping are highly likely to occur, and soft soil is prone to squeezing out between piles, causing excessive settlement outside the pit. To ensure construction efficiency and overcome difficulties such as high excavation difficulty and water-rich sand layers and strongly weathered rock strata, the project department rationally optimized the construction organization, strictly implemented both safety and technical briefings, effectively carried out the leadership shift system for project team members, the on-site supervision system for major milestones, and the team building management system, and vigorously controlled quality throughout the entire process; at the same time, through the "smart construction site integrated platform," real-time monitoring of on-site personnel, machinery, and materials was conducted. During foundation excavation, the project department strictly implemented the "spatiotemporal effect," followed the process requirements of "timely support, support before excavation, layered excavation, and strict prohibition of over-excavation," and strictly controlled the construction quality of the CSM waterproof wall reinforcement outside the pit and other effective measures, ensuring that the deep foundation pit construction smoothly passed through the high-risk period of base slab backfilling, allowing the first section of the foundation pit to successfully "reach the bottom."

It is reported that the Phase II project of Qingdao Metro Line 6 has a total length of 13.85km, all underground, with 10 stations and 3 transfer stations. It starts from Qingxi Station in the west and ends at Xintun Road Station, the starting station of Line 6 Phase I, in the east. It is a backbone line in the old urban area of West Coast New Area, connecting the comprehensive transportation hub Qingdao West Station and Metro Line 13. It can deepen the close connection between the main urban area of West Coast New Area and the peripheral areas, and is of great significance for promoting coordinated development.

Next, the project department will anchor to the goal of building a world-class metro, continue to stay true to its original aspiration and overcome difficulties in subsequent construction, further grasp and refine all work, promote construction production quickly, with high quality and efficiency, and make every effort to ensure that the next stage's main structure topping-out milestone is completed as planned, accelerating the construction of "Qingdao on Rails."