Continuing east from Aoti Station, we arrive at Yongzhong Station, which is the 16th station of the first phase of the S1 Line. On March 1, the reporter saw at the construction site that the station is located below an intersection, part of the underground space construction has been initially completed, and the underground running space for the city express trains has taken shape.

Underground one-level station with dual concourses and four entrances/exits

The Yongzhong Station and the track sections before and after it belong to the 11th bid section of the first phase of the S1 Line. Because the section is 3.1 kilometers long, it is divided into two sub-sections, 11A and 11B, with Yongzhong Station belonging to the 11B sub-section. According to a relevant person from the Construction Branch of Wenzhou Railway Investment Group, the overall task of the 11th bid section is nearly half completed, and the construction progress is at the upper-middle level among all bid sections.

Yongzhong Station is located directly below the intersection of Yongqiang Avenue and Weiken Road in Longwan, i.e., south of Binhai Hotel and Oriental Pearl City, and is the core part of the 11th bid section. The station is an underground one-level station, arranged parallel to Weiken Road. The total scale of the station is about 15,000 square meters, with four ground-level entrances/exits located in the four directions of the intersection, facilitating passenger flow from all directions. At the same time, dual concourses are set up on both sides of the line, on the same level as the platforms.

After the station is completed, entering passengers can enter the non-paid area of the concourse public area on the underground first floor through the four ground entrances/exits, and after ticket sales and inspection, enter the paid area platform level on the same floor. The north and south concourses are connected by internal passages, facilitating passengers traveling in different directions. Exiting passengers can reach the non-paid area on the same floor from the paid area of the platform through the gates, and take the upward escalator to exit the station.

A deputy manager surnamed Wang from the 11B bid section project department said that due to various pipelines within the station construction area, the station does not yet have construction conditions, and he estimates that it will take about 3 months to complete the relocation and modification of these pipelines.

Digging 15 meters deep, supporting with steel pipes while excavating

According to relevant personnel from the Construction Branch of Wenzhou Railway Investment Group, the underground space for the operation of city express trains has a professional term called "foundation pit." The construction of the foundation pit is directly excavated from the ground down, and after construction is completed, the space between the top of the underground space and the ground surface is backfilled with earth.

According to reports, the foundation pit of this section is about 12 meters wide, with its bottom 15 meters below ground. Before construction, the contractor needed to dig deep trenches 30 meters deep and 80 centimeters wide on both sides of the road corresponding to the side walls of the foundation pit, to create reinforced concrete diaphragm walls. "This is equivalent to building a frame for the foundation pit to ensure that surrounding buildings are not affected by subsequent construction," said Zhang Zhiqi, secretary of the 11A bid section project department. After the diaphragm walls are completed, the support during excavation becomes more stringent, so every 4 meters or so of excavation, steel pipes with a diameter of 80 centimeters are used as support until the bottom of the foundation pit is reached.

After the excavation work is completed, the construction personnel first remove the bottom layer of steel pipes and build the bottom slab of the foundation pit, on which the tracks will be laid in the future. Next, the middle partition wall separating the two-way tracks is erected, and then the top slab of the foundation pit is built. After the strength of the foundation pit meets the requirements, the steel pipes at each level are removed, and then bamboo plywood is installed on the side walls and top slab, and the foundation pit work is considered complete. In the final step, workers backfill the space between the top slab of the foundation pit and the road surface, remove the concrete supports, and all main structures are basically completed.

On the same day, the reporter came to the No. 1 work area of the 11A bid section on the west side of Jianzhong Street in Longwan District, where the civil construction of the foundation pit has been basically completed. Near the middle partition wall, there is a passage. Zhang Zhiqi said that this is an evacuation passage. If an accident occurs while the vehicle is running underground, passengers can use this evacuation passage to walk to the nearest station and return to the ground, or through safety doors set up about every 200 meters, cross the middle partition wall to the other side.