YANGGuo-hong.Large Diameter Parallel Pipe Jacking and Auxiliary Engineering Design of Macao Water Supply Project[J].China Water & Wastewater,2025,41(8):83-90.
Large Diameter Parallel Pipe Jacking and Auxiliary Engineering Design of Macao Water Supply Project
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第8期
Page:
83-90
Column:
Date of publication:
2025-04-17
- Abstract:
- Due to the construction of the ship lock at the outlet of the Qianshan Watercourse, it is planned to relocate and renovate the two existing water supply pipes to Macao. Among them, the pipe jacking section of the Qianshan Watercourse approximate 650 m long is the key route of the project, and uses two DN1 800 steel pipes buried at a depth of 15.30 m approximately. In response to the technical difficulties of conventional large diameter single pipe jacking, such as large footprint, long construction period, and significant water quality impact during grid connection, the project creatively adopted the double pipe parallel staggered synchronous jacking construction process. The jacking machine head has been staggered by 30 m alternatively, and the synchronous pushing speed of the double pipes can reach 20 m/d, saving about a month of construction period. The spacing of synchronous parallel pipe jacking has been comprehensively considered based on the disturbance width of the machine head and the effective penetration radius of the thixotropic mud, as well as the impact of pressure water release during pipeline failure. The design net distance between the pipes is 3 m, the inner diameter of working well is 15 m, and the inner diameter of receiving well is 10 m. On the other hand, by optimizing the design of large diameter auxiliary valve wells and using the press?in caisson method to construct the pipe jacking well, it can realize rapid and steady sinking of the well body, effectively control ground settlement and reduce the impact on existing buildings while reducing land use. Finally, organized flushing was carried out to reduce the impact of pipeline grid connection on the current water supply system. The project has been running steadily for over 2 years, and the relevant design experience can be used as reference for similar projects.
Last Update:
2025-04-17