Recently, as a "golden key" was handed over from the construction unit to the operating unit, it marked that all stations on the eastern extension of Guangzhou Metro Line 3 (Panyu Square—Haibang) have successfully completed the "three rights" handover. At this point, all stations and track areas along the line have officially entered the operational commissioning stage. It is reported that the eastern extension of Line 3 is planned to open for operation within this year.

Promote "seamless" connection of the entire business and improve construction efficiency

The eastern extension of Guangzhou Metro Line 3 starts at the existing operating Panyu Square Station of Metro Line 3 and ends at Haibang Station, with a total length of about 9.6 kilometers. From west to east, the stations are Bangjiang, Shiqi South, Haiyong Road, and Haibang. Haibang Station connects with the already opened Line 4. After the entire line is completed and opened, it will facilitate travel for residents on both sides of Yayun Avenue and in Yayun City, and will play an important role in accelerating the formation of the "Greater Bay Area on Rails."

A person in charge of Guangzhou Metro introduced that the environment along the eastern extension of Metro Line 3 is complex, with dense surrounding buildings and structures, and it passes under many sensitive areas such as rivers, the roadbed section of the Beijing-Zhuhai Expressway, and the bridge piles of the elevated section of Line 4, making construction coordination highly difficult. The running tunnels mainly pass through moderately weathered granite, soft strata such as silty fine sand layers, silt, and silty clay layers, clay layers, and unfavorable geology such as upper-soft-lower-hard conditions, which has brought major safety challenges to the tunneling task. In particular, Haibang Station, as the interchange station between Line 3 and Line 4, has complicated underground pipelines. Deep foundation pit excavation, relocation and modification of three ultra-high-voltage gas pipelines, and construction of the station's main structure are carried out in cross-operation, covering almost all construction techniques and methods used in metro construction, posing a huge test for construction.

Facing complex geological conditions and a stringent construction environment, Guangzhou Metro worked closely with participating units such as Guangzhou Construction and Guangzhou Metro Engineering Consulting Company, continuously breaking conventions, strengthening scientific and technological research, optimizing technical plans, improving construction efficiency, and overcoming difficulties such as shield tunneling through main sewage pipes, deep foundation pit excavation in deep original silt strata, operations under high-voltage power towers, pipe-jacking tunnel driving with small spacing, and complex and frequent traffic diversion. During this period, special methods such as the "parent-child cage" and "combined diaphragm wall steel box cage" were also independently researched and applied to assist construction.

During the construction of the main structure of Haibang Station, traditional open-cut construction could not be adopted due to the influence of underground pipelines. The project innovatively proposed a large-section rectangular pipe-jacking mined construction plan and selected the domestically largest cross-section slurry balance combined rectangular pipe-jacking machine, "Dunding No. 1" (with a cross-section of 11.1 meters by 8.1 meters). It adopted a layout mode with a central large cutterhead and rectangular cutterheads on both sides, precisely controlling links such as pipe segment assembly, closely spaced construction of the left and right lines, and ground settlement, effectively avoiding safety risks.

To address the unfavorable conditions that the No. 4 cross passage of the section from Bangjiang Station to Shiqi South Station is located beneath Yayun Avenue, must pass through composite strata, and is relatively long, and considering that the traditional mining method for manual work would not only involve high construction risks but also low efficiency, metro builders took a different approach and applied the mechanical method for cross passage construction for the first time. During this period, they overcame unfavorable conditions such as in-station translation, precise positioning of the shield machine in narrow spaces, large-angle launching and receiving, tunneling in upper-soft-lower-hard and variable composite strata, and stress monitoring of the main tunnel segment.

After entering the electromechanical engineering construction stage, metro builders fully leveraged the advantages of integrated management of civil and electromechanical construction, reasonably arranged processes, strengthened collaboration and integration, and ensured sufficient input of personnel, machinery, and materials at each work face. By fully applying digital management methods, they developed a project management platform based on BIM models, established associations between electromechanical construction models and construction progress and quality, and achieved information and data sharing among all participating parties.

In addition, the project also established a dedicated quality team management team to carry out professional process-based management for the installation of equipment in various specialties and the wiring of control cables, ensuring that the single-machine commissioning of each system succeeds on the first attempt. In terms of system joint debugging, based on typical stations, it guided other stations to optimize the joint debugging process, greatly shortening the overall joint debugging time of the line and reserving sufficient time for subsequent work.

Construction and operation advanced in coordination, clearing obstacles in advance

To ensure the smooth handover of all stations along the line for commissioning, all participating parties jointly formulated detailed acceptance and handover plans. The construction unit proactively organized coordination with the operating unit, promptly reviewed commissioning progress and the progress of on-site problem rectification, took strict alignment with handover standards as the work orientation, checked station handover conditions item by item, and followed up on the progress of functional commissioning of almost all electromechanical equipment across all specialties at the stations. At the same time, by establishing a regular communication and coordination mechanism and organizing multiple benchmarking meetings and commissioning work promotion meetings, it achieved efficient linkage and coordinated progress among multiple units, realized the efficient and rational allocation of resources such as personnel and testing instruments, and effectively improved work efficiency.

It is introduced that after the entire line enters the operational commissioning stage, Guangzhou Metro will continue to promote preparation and planning, organize and coordinate various tasks such as comprehensive joint debugging, project acceptance, fire acceptance, and trial operation safety assessment, so as to provide conditions for the high-quality opening of the entire line for trial operation.

As of now, the civil engineering works of the eastern extension of Guangzhou Metro Line 3 (Panyu Square—Haibang) have cumulatively completed 99%. The "three rights" of all stations and track areas along the line have been handed over. The Guangzhou Xincheng Depot is undergoing remaining civil engineering and electromechanical construction.