On September 2, 2024, the circular pipe-jacking project for the power cable tunnel on the Zhufu Line power plant exit section in Nansha District, Guangzhou, constructed by China Railway Guangzhou Engineering Group Co., Ltd. and jacked by Guangzhou Jintu Geotechnical Engineering Technology Co., Ltd., was successfully launched.

Pipe jacking launch photo

This pipe-jacking project is located in Nansha District, Guangzhou. The project starts at the Zhujiang Power Plant and ends at the cable terminal in Hudiezhou Park. The project is divided into 3 pipe-jacking sections, with lengths of 325.8 m, 551.3 m, and 305.1 m respectively, and a total jacking length of 1,182.2 m. The pipe-jacking works pass beneath Jinzhou Stream, Huanshi Avenue North, Zong'er Road, Jingang Avenue, and Hudie Park, where road traffic is heavy and passenger flow is large; the surrounding environment of the pipe-jacking sections is relatively complex, with buildings (structures) such as residential houses, power towers, and high-voltage transmission line towers distributed nearby.

Satellite plan view of pipe-jacking construction

The cross-sectional dimensions of the pipe-jacking works are DN2600 and DN3000, with the longest single jacking length of approximately 551.3 m, a cover depth of 7.55–9.28 m, and a minimum horizontal curvature radius of 800 m. The works mainly pass through strata including silt, sandy clay, and strongly to slightly weathered granite, among which the strength of slightly weathered granite reaches 103 MPa. This project will deploy 3 pipe-jacking machines for the jacking construction.

Pipe segment cross-section drawing

Project characteristics

1. The longest jacking length of the DN3000 pipe jacking is 551.3 m, which is a long-distance pipe jacking with large frictional resistance during jacking construction.

2. The DN2600 and DN3000 pipe jackings mainly pass through strata of silt and strongly to slightly weathered granite. The silt layer has relatively poor soil stability and low bearing capacity, making the machine head prone to pitching during launch; moreover, the site has a high groundwater level, making water and sand inrush likely during launch and reception, so the overall jacking construction risk is high.

3. The pipe jackings of this project pass beneath urban main roads, where road vehicle and passenger flow is relatively large, and construction imposes high requirements on road deformation control.

4. The DN3000 pipe-jacking section involves curved jacking with a minimum curvature radius of 800 m, making axis measurement and control difficult.

5. During the jacking of the DN2600 and DN3000 pipe jackings, the strata passed through are mainly silt and strongly to slightly weathered granite, among which the granite rock strength is high, reaching a maximum of 103 MPa. Due to terrain undulation, the strata vary greatly and are unevenly distributed. The pipe jacking is driven through water-rich soft-upper and hard-lower strata, making jacking attitude control difficult and easily leading to large axis deviation and causing significant stratum deformation, so the overall construction is difficult.

Guangzhou Jintu will strictly follow the design drawings and the owner's requirements, carefully organize construction, apply scientific management, strictly control every technical aspect of construction, carry forward the craftsman spirit, solve the key and difficult points in the project, and complete this power cable tunnel pipe-jacking construction task with high quality and high efficiency.

Integrity, pragmatism, innovation, and development collectively embody Guangzhou Jintu's business philosophy and corporate spirit. Integrity is the cornerstone, pragmatism is the spirit, innovation is the driving force, and development is the absolute principle. Jintu people work together in unity and collaboration, give full play to their wisdom and talents, and overcome one obstacle after another, helping the company become a benchmark and leading enterprise in China's urban underground space and underground engineering construction industry!